I was responsible for the Turbo C (later Borland C/C++) run-time library in the late 80s and early 90s.<p>Tanj Bennett created our original 8087 floating point emulator. It was real mode, 16-bit code, that kept an 80-bit float in five 16-bit CPU registers as a working value during its internal math calculations. If you ever coded for the PC you will appreciate just how precious register space was on the 8086/8088.<p>It's been a few decades and my memory is fuzzy but I don't recall any critical places where the registers had to be saved and restored. He choose math algorithms and code paths specifically to keep all five live at all times. Tanj's code flowed with an economy of motion that brought to mind the artistic performance of a professional dance troupe. I did not have the math skill and could not have ever created it as he had. It brought me genuine pleasure just to read his code.<p>Eventually, it came time to port it to 32-bits (real and protected modes.) I wrote new exception handlers and replaced the instruction-decode logic with a nice table-driven scheme but did not touch the core math library. It still ran in 16-bits under the hood exactly as Tanj designed it.<p>Tanj, if you happen to see this, I have fond memories of your emulator. It was beautiful.
Nobody has mentioned Knuth’s corpus of work in Pascal-Web for the TeX ecosystem. This is code written for an era where there wasn’t an ecosystem of libraries for common tasks and even things like being able to access a file in random access order couldn’t be counted on. Even 7-bit ASCII couldn’t be counted on as a given (EBCDIC-based IBM mainframes were a significant element of the computing landscape still).<p>Against all that, Knuth wrote code that could be ported to other systems (I first used TeX on an IBM mainframe running VM/CMS, then later on a VAX minicomputer running VMS, then on a PC with DOS, PC with OS/2, PC with Windows and now a Mac with OS X/MacOS. His presentation of code and internal documentation intermingled is something which I could see still being useful now, although sadly, literate programming seems all but dead now. I still go back to Knuth’s code to understand how to solve some problems on occasion even though it’s about 30 years since I last wrote a line of Pascal.
Postgres code is very good, redis as well. Some of the core parts of Linux also totally worth learning from.<p>I also remember how Qt UI code and docs were a revelation after the nightmare of win32 and related frameworks.<p>Bellard's original Tinycc was very entertaining and took a while to digest.<p>Most old and well-maintained projects are worth learning from.<p>Apart from some local tips and tricks what is more important is understanding that there's nothing special about other people's code.
One of the most surprisingly clear code bases is LLVM. It’s an old complex beast, yet it’s organized beautifully.<p>I mean, it has a lot of essential complexity but little accidental complexity.<p>That’s usually what I strive for when coding. Complexity is sometimes unavoidable, that’s fine, that’s why it’s essential. However, avoidable complexity should be… well… avoided.
I haven’t read all of it, but the Principia source code has a comprehensive units system and makes effective use of Unicode: <a href="https://github.com/mockingbirdnest/Principia/" rel="nofollow">https://github.com/mockingbirdnest/Principia/</a><p><a href="https://github.com/mockingbirdnest/Principia/blob/master/astronomy/orbital_elements_body.hpp#L376-L420" rel="nofollow">https://github.com/mockingbirdnest/Principia/blob/master/ast...</a> is a decent example of both:<p><pre><code> // We compute the mean rate (slope) of the mean anomaly M(t), the mean
// argument of latitude u(t), and the longitude of the ascending node Ω(t).
…
Product<Angle, Square<Time>> ʃ_Mt_dt;
Product<Angle, Square<Time>> ʃ_ut_dt;
Product<Angle, Square<Time>> ʃ_Ωt_dt;
…
ʃ_Mt_dt += (Mt + previous_Mt) / 2 * dt;
ʃ_ut_dt += (ut + previous_ut) / 2 * dt;
ʃ_Ωt_dt += (Ωt + previous_Ωt) / 2 * dt;
…
anomalistic_period_ = 2 * π * Radian * Δt³ / (12 * ʃ_Mt_dt);
nodal_period_ = 2 * π * Radian * Δt³ / (12 * ʃ_ut_dt);
nodal_precession_ = 12 * ʃ_Ωt_dt / Δt³;
</code></pre>
The advantages are concise notation plus compile–time guarantees that the units work out. I don’t care much for C# in general (or C++ for that matter), but I like the results here.<p>Sounding out the Greek names occasionally used as release names is always fun too.
It’s not the best, far from it, but it was fascinating to me so I will share.<p>I used to work for a large newspaper. Engineering wasn’t the focus of the business, it was only a means to an end, it was just something they needed to have a competitive website. As a result, the churn rate was very high. But more interesting there was also a very high return rate. Engineers would come and go and return and leave again all the time.<p>As a result, the code base was a path work of various engineers with various skill level, different directions by different heads of engineering, repurposed old projects, legacy code and last minute additions by urgent request from the editors, among others.<p>The part I was most familiar with was what I can only describe as a sort of next.js but unlike it, it wasn’t planned or designed but rather it sort of grew organically over the years.<p>The fascinating thing to me was precisely this phenomenon. Some projects have a clear design and purpose and are built so from the start. Sort of like a building or a mechanical clock.<p>Others just evolve over time, they change, mutate, evolve, incorporate other bits. More like a biological organism or perhaps nature taking back a derelict settlement.<p>At first as you can imagine it was difficult to wrap my head around it. But in time, I started to see the beauty in it. It had historical bits. There was code written in 2010 that ran in 2020. Others you could tell little habits of the writer. Not everything gets stamped out by the linter. There was this guy who wrote “class ClassName extends React[“Component”]” - I have no idea why but I would run into code written by him and immediately recognise, ah yes, that’s that guy.<p>It’s certainly not an example of a good code base, but to me was interesting being able to see the code as a living organism with a history and fingerprints of it’s creators rather than a well designed machine.
I will always have a soft spot in my heart for Django, the python web framework, even though I don’t use it anymore. <a href="https://www.djangoproject.com/" rel="nofollow">https://www.djangoproject.com/</a><p>When I was still learning to code, I spent hours and hours and hours poking around the Django source code. In particular I was fascinated by the metaprogramming used in the Model and Query objects, and I ended up learning a ton about how Python works under the hood.
My favourite is SerenityOS: <a href="https://github.com/SerenityOS/serenity" rel="nofollow">https://github.com/SerenityOS/serenity</a><p>Not only is the code itself structured much more pleasantly than I ever suspected possible in C++, huge parts of it were also recorded while they were being written (see <a href="https://www.youtube.com/c/AndreasKling" rel="nofollow">https://www.youtube.com/c/AndreasKling</a>) so you can see and hear the process that led to the final product.<p>Some of the code is quite gnarly, which is to be expected from a repo containing an entire operating system, containing everything from the kernel to a bespoke web browser.<p>However, as SerenityOS isn't trying to be a UNIX clone, its C++ oriented APIs are a nice breath of fresh air compared to the barebones C that Linux and friends use.
Poul-Henning Kamp was on a FreeBSD podcast (~15 years ago) and did an approachable walkthrough of the performance considerations he made when he created varnish. It stoked some serious curiosity in me, i was working on a system that heavily cached IO in userspace (and paid LOTS of money to do so - we're talking 100s of nodes) and here he was saying things like (i'm paraphrasing here) it's pretty dumb to cache your data from disk in userspace. One thing led to another and i scored a nice bonus that year. By the end of that year i had learned about (and put to good use) techniques like IRQ pinning and of course understanding the caching tunables in the linux VFS layer. I can't find the podcast to link to but this document is pretty much on the money for what i remember hearing <a href="https://varnish-cache.org/docs/trunk/phk/notes.html" rel="nofollow">https://varnish-cache.org/docs/trunk/phk/notes.html</a><p>Another one is the Postfix codebase by Wietse Venema. It was notable because it's basically had the square root of 0 vulnerabilities despite being written in C and being one of, if not the most popularly deployed MTAs in the world (so basically a constant target for hack attempts - contemporary products like Exchange were basically a laughing stock for vulns in that time period). Anyway, the architecture of that codebase is bordering on beautiful. It's a total goldmine.<p>Bonus - a popular code base that made my eyes bleed, nginx. I think it's basically been re-written today but the earliest versions of it were horrible to read. It was fast back then but it was like some sick twisted joke of how to write code. This is not to take away from whoever created it, they still created a monumental shockwave when they released nginx, it was far more performant that anything else.
I had quite some pleasure working with the Source Engine gameplay code. (Some 10 years ago now)<p><a href="https://github.com/ValveSoftware/source-sdk-2013" rel="nofollow">https://github.com/ValveSoftware/source-sdk-2013</a><p>It is not that the quality of the code is high, but just that it is well organized, and everything seems like it was written by a beginner. That makes it wonderfully easy to read and follow the logic.<p>Since have played around with the Source Engine, I follow the KISS principle with coding with high priority. Rarely trying to be clever, or try to over-do abstractions.
I've never seen C code as clear and well documented as tcl. E.g. <a href="https://github.com/tcltk/tcl/blob/main/generic/tclUtil.c" rel="nofollow">https://github.com/tcltk/tcl/blob/main/generic/tclUtil.c</a>, though more examples in that project are not hard to find.
Maybe not revolutionary, but I think this article about static binary translation is a great introduction to the topic:<p><a href="http://www.gtoal.com/sbt/" rel="nofollow">http://www.gtoal.com/sbt/</a><p>(see also the "Virtual Machines" book by Smith and Nair, ISBN-13 978-1558609105, if you are interested in this topic).<p>I can also recommend John Lions' "Commentary on the Sixth Edition Unix Operating System" - <a href="https://warsus.github.io/lions-/" rel="nofollow">https://warsus.github.io/lions-/</a>, Douglas Comer's Xinu (<a href="https://xinu.cs.purdue.edu" rel="nofollow">https://xinu.cs.purdue.edu</a>) as well as Niklaus Wirth's "Compiler Construction" (<a href="https://people.inf.ethz.ch/wirth/CompilerConstruction/CompilerConstruction1.pdf" rel="nofollow">https://people.inf.ethz.ch/wirth/CompilerConstruction/Compil...</a>) and Project Oberon (<a href="http://www.projectoberon.com" rel="nofollow">http://www.projectoberon.com</a>).
Well, eye opening was the C++ source code I was able to work with at a previous company, they were an automotive HMI developer company. They had really strict and well planned code structure that just hit a chord with me.<p>Can't provide source though on that one, as it's a propietary engine.
Recently I've enjoyed reading the source code to Sokol, lot's of really good decisions there and I love the minimal C -style structure:<p><a href="https://github.com/floooh/sokol" rel="nofollow">https://github.com/floooh/sokol</a>
Contrarian answer: Conway's Game of Life in Dyalog APL <a href="https://www.youtube.com/watch?v=a9xAKttWgP4" rel="nofollow">https://www.youtube.com/watch?v=a9xAKttWgP4</a><p>It feels like the logical end state of "clever" code, for better or for worse. Or, alternatively, what happens when a standard library is gigantic but each keyword is 1-2 characters.
I thought I wrote good Perl code until I read the Perl core modules. Like night and day.<p>Busybox and uClibc are great examples of efficient C code. I submitted a feature, and they basically rewrote it to be less crap, and that taught me a ton.<p>Hard to know what good Python code is. Everyone seems to use some framework that fundamentally changes how you write apps. "best source code" is probably just what's best for that specific kind of work.
Not a single code-base, but The Architecture of Open Source Application books are worth a look to help get started reading various sources: <a href="https://aosabook.org" rel="nofollow">https://aosabook.org</a>
Not exactly source code, but the <a href="https://frinklang.org/frinkdata/units.txt" rel="nofollow">https://frinklang.org/frinkdata/units.txt</a> is the most fascinating configuration file I've ever read. It is also the only one that I occasionally re-read just to enjoy the commentary on the standards organizations that are responsible for some of the complexity.
I like the TypeScript compiler source (in TypeScript.) It's clean, easy on the eyes with well placed white space and just the right amount of comments.<p><a href="https://github.com/microsoft/TypeScript/blob/main/src/compiler/program.ts" rel="nofollow">https://github.com/microsoft/TypeScript/blob/main/src/compil...</a>
Surpised no one has mentioned the Nethack source, small codebase going on close to 40 years.<p><a href="https://github.com/NetHack/NetHack/tree/NetHack-3.7/src" rel="nofollow">https://github.com/NetHack/NetHack/tree/NetHack-3.7/src</a>
Apple's Swift source looks nice[0]. So does Darwin[1].<p>They have done a lot of work on structure and documentation, since the docs are auto-generated.<p>I have taken a lot of inspiration from them.<p>The Adobe APIs[2] were also excellent, but I'm not sure they are open for browsing, anymore.<p>[0] <a href="https://github.com/apple/swift" rel="nofollow">https://github.com/apple/swift</a><p>[1] <a href="https://github.com/apple/darwin-xnu" rel="nofollow">https://github.com/apple/darwin-xnu</a><p>[2] <a href="https://developer.adobe.com/photoshop/api/" rel="nofollow">https://developer.adobe.com/photoshop/api/</a>
I quite like the FreeBSD src tree, as it comprises both the system kernel as well as the userland applications. The folders are organized similarly to the OS file system hierarchy, which I find helpful for navigating the source tree. I found it accessible to slowly learn how various parts of the OS work under the hood and compound my knowledge faster due to less context shifting, since it’s self-contained in one source tree.<p><a href="https://github.com/freebsd/freebsd-src" rel="nofollow">https://github.com/freebsd/freebsd-src</a>
I have a soft spot for Musl libc just for how clear it is considering it's one of the most widely used libraries in containers and has to perform well in the real world.<p><a href="https://musl.libc.org/" rel="nofollow">https://musl.libc.org/</a>
Maybe I've just been exclusively working on really boring stuff, but there are no examples that particularly come to mind.<p>There are programs and programmers that impress me, and once in a while I'll come across an interesting algorithm, but I can't really think of any code that is anything more than just code.<p>It's either too simple to do anything I'm interested in, too full of ugly hacks like most large programs, or deals with math and algorithms way above my understanding, to the point where I probably haven't even tried to read it.<p>Some of most memorable bits or code for me are the examples for frameworks and libraries, but those are more impressive for the code that isn't there, rather than the code that is.<p>I love declarative work(Not so much pure functional, but things like CSS and CAD constraints where a solver figures out how to make your intent happen) but again, that's notable for the code that isn't there.<p>I also really like hardware workarounds. It's so cool to be able to have software that runs fine on bad hardware. It's not that common, but occasionally you can pull it off in a reliable way that really is just as effective as using better hardware. Seeing pure code replace hardware is kind of like a further development of replacing mechanical stuff with solid state chips.<p>I really just don't care about code itself very much. I don't want to write bad code, but I only care about good code in as much as it will actually benefit the project. Once it's good enough, features or architecture improvements or unit tests or something might be more important, and interesting or clever code might bring the project down.<p>If I'm reading your code, I'm probably either adding to it and complaining that it doesn't have an API hook already there, or fixing a bug.<p>If I'm using but not reading your code I'm probably happily assuming it's great, if it's a popular trusted thing.
A few that come to mind..<p>Hand-written compiler for WebAssembly Text format to binary - <a href="https://raw.githubusercontent.com/stagas/wat-compiler/main/story.txt" rel="nofollow">https://raw.githubusercontent.com/stagas/wat-compiler/main/s...</a><p>Gameboy emulator implemented in C, that also runs in the browser - <a href="https://github.com/binji/binjgb" rel="nofollow">https://github.com/binji/binjgb</a><p>QuickJS Javascript Engine - <a href="https://github.com/bellard/quickjs" rel="nofollow">https://github.com/bellard/quickjs</a><p>The TypeScript language and compiler - <a href="https://github.com/microsoft/TypeScript" rel="nofollow">https://github.com/microsoft/TypeScript</a>
The Racket implementation for protocol buffers. The generated code is just an S-Expified version of protobuf source files, all macros which generate actual protobuf implementation at runtime lol. I don't know why I was surprised.<p><a href="https://docs.racket-lang.org/generator/index.html" rel="nofollow">https://docs.racket-lang.org/generator/index.html</a><p>Can't find source code online. I browsed the code in emacs with racket-xp-mode go to definition after installing it via raco pkg install. Could probably use DrRacket instead of emacs/racket-xp-mode.<p>I had to read the source code to find out what the specific names of the proto creators, accessor, mutator functions would be.
The 8086 Assembly source code of the MikeOS operating system is remarkably readable and easy to understand for such low-level software <a href="http://mikeos.sourceforge.net" rel="nofollow">http://mikeos.sourceforge.net</a>
cperciva writes easily the most approachable, understandable code I’ve ever come across, e.g.:<p><a href="https://github.com/tarsnap/kivaloo" rel="nofollow">https://github.com/tarsnap/kivaloo</a>
The NetSurf web browser, and its modular parts (in C).<p>Quite simple and straightforward, and very modular. For a browser.<p><a href="https://www.netsurf-browser.org/" rel="nofollow">https://www.netsurf-browser.org/</a><p><a href="https://source.netsurf-browser.org/" rel="nofollow">https://source.netsurf-browser.org/</a>
I see FreeBSD was mentioned in a different comment, but I’ll cast a vote for NetBSD.<p>The kernel abstractions that allow for portability make the code quite easy to read. Back in the day, I was able to write a file system from scratch by just reading the code of other file systems. The build system is also pretty amazing (allowing you to cross build the whole OS for any hardware target from many other OSes) and not too hard to follow. The source tree is structured in a way that makes a lot of sense (IMHO better than FreeBSD).
I don't know if it was the best, but one of the codebases that really helped me out in the mid-90s was XEmacs. It was portable to many kinds of systems and had lots of features that most applications never have to worry about (e.g., an embedded interpreter). I also got value out of GNU Emacs but XEmacs tried harder to be a good citizen on the X desktop and there were lots of lessons learned in there that I was able to leverage for the applications I was building at the time.
Ok just to come at this from another angle: my own (embedded C) code, after it had been gone over by a much more experienced and skilled maintenance programmer to bring it up to company standards. It wasn’t beautiful, even then, but it was crisp, super readable, and ironically closer to how I remembered it than the original. He hesitated to show it to me! Programmer ego and tact are funny things. Humbling, sure, but on the whole I was delighted.<p>The best - it compiled to the sane hex file.
Recently my favorite is core contracts of Uniswap V3 - <a href="https://github.com/Uniswap/v3-core" rel="nofollow">https://github.com/Uniswap/v3-core</a> Lots of nice ideas for a restrictive computing platform like EVM.
The standard library of Julia, especially with the possibility to just enter `@code someFunction(params)` in the REPL to see the source of the method that the call would be dispatched to, the source can basically function as a second layer of documentation (the first layer being docstrings that are part of the source as well, but are usually accessed either via the IDE, or the help-mdoe of the REPL).
OpenBSD source code[1], because I think it represents good design.
The code is as little as possible and easily understandable.<p>[1] <a href="https://cvsweb.openbsd.org" rel="nofollow">https://cvsweb.openbsd.org</a>
Eye-opening but probably not "best": the Nullsoft Installer, circa 2002 (<a href="https://github.com/kichik/nsis" rel="nofollow">https://github.com/kichik/nsis</a>). Its goal, besides being an installer, was to produce a small binary. So the source was remarkably pithy, which taught me a lot about being direct and to-the-point rather than aiming for beautiful abstractions or reusability.<p>Similar with Notch's Left4KDead, which implemented a fun zombie game for a Java small-code competition. A mirror of the original source is here (<a href="https://github.com/codingcampbell/Left-4k-Dead" rel="nofollow">https://github.com/codingcampbell/Left-4k-Dead</a>). I rewrote it in JavaScript as a Chrome App, in the process refactoring for readability (and sacrificing some of the code's beauty). <a href="https://github.com/sowbug/ChromeLeft4kDead" rel="nofollow">https://github.com/sowbug/ChromeLeft4kDead</a>
I wish there was a website like a code wall where you could see great code snippets and comments on why they are so great. Would be like a code museum. If anyone remembers the old coffee script source code with the explanation on the left, it's something like that I had in mind.
The Smalltalk-80 core classes. Some parts left me breathless on first reading in their beautiful simplicity, and some burnt permanently into my brain. Class Boolean, for example. I could probably reproduce it exactly now after not looking at it for decades.
The one that I didn't have to read.<p>A mistake i see many engineers commit is obsess over their code and how "pretty" it is. What they seem to forget is that code is only read when it isn't doing what it's supposed to do. Granted when you do have to read it there are good and bad examples, but the question you should ask yourself is not "how can I make this code easier to read?" But "how can I make sure noone has to read this code". The code that performs this job is not always pretty. If it is impossible to make the code bulletproof then the best bet is usually to just make it really simple. Good code is nonexistent and if it has to exist it is boring.
I remember liking the java sdk java source. Great small focused functions and nice use of newlines. You could tell the developers were forged in an era without syntax highlighting and large horizontal screens. Extremely scannable.
I don't know if it is the most elegant, or concise, or l33t, but I am in love with Polly <a href="https://github.com/App-vNext/Polly" rel="nofollow">https://github.com/App-vNext/Polly</a>
I am definitely biased, but in general I like go source code? Meaning golang itself, and the standard library<p>every time I am not fully sure what some function from golang std library does, I just click away to its source code and it’s quite clear
The {BSD/OS, Free and Net}BSD sources in the mid-90s, coming from Linux and a source license for a commercial unix, both of which were mostly undocumented and didn't have any version control. The commercial unix was really grody, with lots of copy/paste of the same function with different bugs each time, and comments with bug numbers that meant nothing to us and didn't explain a thing.<p>The BSD sources were sanely laid out, documented and had a beautiful coding style that made the code easy to read. Free- and NetBSD even had version control.
Perhaps not the "best" source code I've ever read, but libVF.io had some beautiful code for what's generally gnarly system-glue code.<p>The libVF.io iommu setup code is a good example and inspires me to think that system-glue code doesn't need to be gross or impenetrable:
<a href="https://github.com/Arc-Compute/LibVF.IO/blob/master/src/libvfio/control/iommu.nim" rel="nofollow">https://github.com/Arc-Compute/LibVF.IO/blob/master/src/libv...</a><p>Another one I've appreciated reading (and learned more about 2d graphics from) is Pixie, a 2d graphics library written in Nim. It's strongly affected how I write similar code.<p>Here's the implementation of a fair subset of SVG paths:
<a href="https://github.com/treeform/pixie/blob/master/src/pixie/paths.nim" rel="nofollow">https://github.com/treeform/pixie/blob/master/src/pixie/path...</a><p>And one last one for basic algorithms which I'd use to teach intro to data structures any day:
<a href="https://github.com/nim-lang/Nim/blob/version-1-6/lib/pure/algorithm.nim" rel="nofollow">https://github.com/nim-lang/Nim/blob/version-1-6/lib/pure/al...</a><p>Of course Knuth's original code is still some of the best classic code. K&R's original C book is a classic.<p>(edited formatting and tweak descriptions)
PostgreSQL comes to mind (eg: see the query planner [0]). It is surprisingly easy to read through lots of interesting parts and see how they are working.<p>[0] <a href="https://github.com/postgres/postgres/blob/master/src/backend/optimizer/plan/planner.c#L283" rel="nofollow">https://github.com/postgres/postgres/blob/master/src/backend...</a>
Since TeX and LLVM were already mentioned, I will casually mention the comments in Laravel's codebase which are all three lines long with each line exactly three characters shorter than the previous line. The art of computer programming at work.<p>Example (config file, but the entire codebase is like that): <a href="https://imgur.com/UnIUZmZ" rel="nofollow">https://imgur.com/UnIUZmZ</a>
This might be pretty controversial, but the Chromium source code has been a pleasure to work with for a few years. I was working on a proprietary fork of Electron and it was a delight to work with that code base vs some of the in house code I integrated into it. The web code search was also awesome to use.<p><a href="https://cs.chromium.org/" rel="nofollow">https://cs.chromium.org/</a>
LevelDB by Jeff and Sanjay.<p><a href="https://github.com/google/leveldb" rel="nofollow">https://github.com/google/leveldb</a>
Not that I understand any of the organic science behind it, but Timothy Stiles' Poly is some of the most beautiful Go code I've seen: <a href="https://github.com/TimothyStiles/poly" rel="nofollow">https://github.com/TimothyStiles/poly</a><p>Blew my mind reading through it, honestly. Just perfect.
While at Grad school, before taking a course on Systems programming, I spent a few days reading through Redis source code. It felt almost like poetry.. I haven’t had that level of motivation or time to read open source code like that again.. so there may be better examples.. but this was my best…
I like Piumarta's code <a href="https://piumarta.com/software/maru/maru-2.4/" rel="nofollow">https://piumarta.com/software/maru/maru-2.4/</a><p>bsd code is clean<p>minikanren<p>some old lisp (le lisp or eulisp I forgot)
Here is the best code I have seen:<p>Yes, you are right. It is empty. The best code there is - is the code you did not had to write. It have no bugs, no latency. I am not being sarcastic here. I truly think that less code is better.
I found the RetroArch source (<a href="https://github.com/libretro/RetroArch" rel="nofollow">https://github.com/libretro/RetroArch</a>) very accessible, when I added a simple title sanitisation it was easy to figure out what I had to change and where the changes needed to be. The accessibility of the source was particularly helpful as it was the first non-trivial C code I had come in contact with.
Idk about the best, but, this[1] implementation of hierarchical state machines is beautiful. It uses a few different template metaprogramming tricks to resolve state transitions at compile time! It's truly beautiful.<p>[1] <a href="https://accu.org/journals/overload/12/64/heinzmann_252/" rel="nofollow">https://accu.org/journals/overload/12/64/heinzmann_252/</a>
Last summer, I followed the step by step code in Crafting Interpreters by Robert Nordstrom (<a href="https://craftinginterpreters.com" rel="nofollow">https://craftinginterpreters.com</a>).<p>Beautiful c code. As a 30+ year programmer, one new thing really stuck with me. He wrote all comments as sentences: first letter capital, finish with a “.”.
I know this isn't what you were looking for...but the literal source code for this website: view-source:<a href="https://www.lingscars.com/" rel="nofollow">https://www.lingscars.com/</a>
D3.js was a pleasure to read. Especially as a developer who was starting to get out of my junior phase and really understand what I was doing in terms of JS.<p>It’s a very simple code-base in many ways. At the time it was 10k lines of mostly short pure functions.<p>The code examples were also really nice and explained a lot about how to work with SVG.<p>I owe some Thanks to Mike Bostok and his fellow developers.
Since diving into stable diffusion, I found the original code not very well organized not factored.<p>Then trying and looking at <a href="https://github.com/geohot/tinygrad" rel="nofollow">https://github.com/geohot/tinygrad</a> which can implement SD, it’s really well written and ideas well organized, concise, and it works on multiple platforms well.
my choice would-be Professor Niklaus Wirth’s source code for “Tiny Pascal” in his seminal book “ Algorithms + Datastructures = Programs.” Here is a link: <a href="https://en.m.wikipedia.org/wiki/Algorithms_%2B_Data_Structures_%3D_Programs" rel="nofollow">https://en.m.wikipedia.org/wiki/Algorithms_%2B_Data_Structur...</a><p>That compiler served as the blueprint for Borland tools.<p>philippe@fullpower.com
I'm probably biased, but I particularly enjoyed going through mpv - <a href="https://github.com/mpv-player/mpv" rel="nofollow">https://github.com/mpv-player/mpv</a><p>I always found much of the FFmpeg API very unintuitive and much of what I now know about it I learned from reading through mpv. Hardware accelerated encode/decode, etc.
I don't know if it's the best code I've ever read but this emulation library [0] of 8 bits computers is pretty well written, documented and designed: <a href="https://github.com/floooh/chips" rel="nofollow">https://github.com/floooh/chips</a>.<p>It's a good way to document old hardware with emulation code.
I like the redis source code and WebTorrent<p><a href="https://github.com/webtorrent/webtorrent" rel="nofollow">https://github.com/webtorrent/webtorrent</a><p><a href="https://github.com/redis/redis" rel="nofollow">https://github.com/redis/redis</a>
Backbone.js has an annotated source code page <a href="https://backbonejs.org/docs/backbone.html" rel="nofollow">https://backbonejs.org/docs/backbone.html</a> which I found very interesting at the time.
If you're looking for C, ReactOS. Example: <a href="https://doxygen.reactos.org/d3/d60/ntoskrnl_2io_2iomgr_2file_8c_source.html" rel="nofollow">https://doxygen.reactos.org/d3/d60/ntoskrnl_2io_2iomgr_2file...</a>
I found the Blender codebase very intriguing. Overall just amazing piece of software and lots to learn from <a href="https://github.com/blender/blender" rel="nofollow">https://github.com/blender/blender</a>.
I can highly recommend checking out <a href="http://aosabook.org/en/index.html" rel="nofollow">http://aosabook.org/en/index.html</a>
Always liked reading the code in src.zip from the java sdk. Not too dense. Really dislike reading scala or kotlin code, though, feels like perl back in the days. But saves a lot of boilerplate.
Back in the 90s I enjoyed Nethack and Perl sources, had a hard copy of both. Both looked somehow human, with witty remarks and outright quotations from holy texts in case of Nethack.
All of the PC/GEOS source code...
<a href="https://github.com/bluewaysw/pcgeos" rel="nofollow">https://github.com/bluewaysw/pcgeos</a>
Linux Kernel source is very good.<p>Wt[0] source code is also good.<p>[0] <a href="https://github.com/emweb/wt" rel="nofollow">https://github.com/emweb/wt</a>
Of course the one I wrote few months ago! When I re-read it today I realize how good I was at foreseeing all the problems that would eventually arise. The code has descriptive comments that explain not just what the code is doing but what it is supposed to do. I was very impressed with not just 100% line coverage but also complete branch coverage by rock solid unit tests. Sorry can't share the link because code is proprietary.