I appreciate the Open Source community and all the positive things its doing for people and places. For instance, the GPL makes it easy to enter the market without a huge time investment into product development.<p>That being said, what are some cons to using Open Source code when developing applications for the masses? For example, is building a social network or designing a template using a GPL software package a bad business plan?<p>I just want to know where to start. Maybe the question I should be asking is something like this... What type of software is the Fortune 500 using and why?
There are in fact many licenses that meet the open source definition, and any concerns about the restrictions of one might be dealt with by looking only at projects based on other licenses: <a href="http://www.opensource.org/licenses/category" rel="nofollow">http://www.opensource.org/licenses/category</a><p>For example, basing a business on <i>GPL</i> as you stated may be a problem because it would compel everything in the stack (including something unique built on top of established code) to be opened up...so it would be hard to build something truly competitive without showing all your cards to your competitors. Other open source licenses such as MIT's have fewer restrictions and amount to preserving copyrights and the right to reuse but without any warranties.<p>Of course you can only build on code that is "compatible" with the license you choose. There may be solutions that are only available under GPL licenses, in which case you have to decide to live with those restrictions or build your own.
You haven't really given us enough information to answer your question. In fact, I suspect you haven't yet asked the question(s) you really want/need to ask. I think you need to spend some time getting familiar with the top most popular F/OSS licenses, and the implications of each of them. There's a really good book on that very topic titled <i>Understanding Open Source and Free Software Licensing</i>. I recommend you read it for a good introduction:<p><a href="http://oreilly.com/catalog/osfreesoft/book/" rel="nofollow">http://oreilly.com/catalog/osfreesoft/book/</a><p><i>For example, is building a social network or designing a template using a GPL software package a bad business plan?</i><p>Using, or not using, F/OSS isn't a business plan, it's just a detail - one element of many in a business model/plan. Whether or not it's a bad idea would depend on the other elements of said model. That said, Red Hat and others have proven the validity of selling F/OSS, if that's what you're getting at.
You can't link to GPL-incompatible code if you're going to distribute the result. If you want to maintain an exclusive right to sell out (which worked well for MySQL AB), you have to get copyright assignments from day one, not just accept GPL'd patches. Some people won't contribute to GPL projects on principle, though I don't think anyone knows how that number compares to people like me who won't contribute to BSDL projects.