I am author of a key-value database library (http://hamsterdb.com) which is released under the Apache license (open source, free to use for commercial applications etc). And I just finished working on my commercial add-on product, the "pro" version which is closed source and for paying customers. hamsterdb's design is similar to a column-store, and the pro version has additional features like compression, SIMD, encryption (there will be more in the future).<p>Now I wonder if I need to offer a trial version for evaluation purposes for the pro version, and if yes - how? hamsterdb is a C/C++ library with many dependencies to libc and other system libraries. Publishing pre-built libraries will work on Windows and maybe MacOS, but other systems like linuxes and embedded platforms will be extremely difficult.<p>My first idea is to release the 30day evaluation version in source, but heavily obfuscate the sources. However, after a few days of trying to get everything running, I had to realize that the obfuscation tools are either very immature, no longer maintained or way too expensive.<p>So maybe I should not release an evaluation license at all, but simply allow buyers to get a refund after 30 days? In that case I am not able to protect my IP, and people can continue using the pro version after the refund. Also, refunding means that there will be additional transaction costs for international money transfers, which can be quite costly. But I have zero development/maintenance effort, which would be very nice and lets me focus on the core features.<p>Now i'm kind of lost and not sure which way to go. Any advice is appreciated!
That is truly an uncomfortable situation. Without any deeper knowledge about HamsterDB or your pro version, you might consider offering your service as SaaS and charging for that. Of course this won't work with all your pro features such as compression or encryption (or maybe it could work in some innovative way).<p>For instance you could charge for painless DB hosting, so users do not have to worry about complicated setups and can immediately use HamsterDB after signing in.<p>EDIT: But you can still go for the 30 day money back guarantee with the exposure of the pro version's source. If that fails you still can decide to switch to a SaaS model.
You said it's a commercial add on product, how big is the target company? If we're talking enterprise it seems really unlikely they're going to be using software without a license regardless of ease. You most likely can't stop pirates but will they be notable?