Hi,
I would like to open source my complete application and I don't mind at all people using my code where-ever as long as they keep the copyright notice of the work. I also need food on the table, which license allows me to have some money if say a commercial site/company wants to use the code?
Does it really matter which license I choose? I can just have a "paypal donate" button and choose a liberal license?
any help.
You could follow the MySQL model and dual license your code under the GPL and a commercial license. See here for their license terms
This way anyone who complies with the GPL license gets your code for free. Anyone with a commercial app that isn't GPL compliant has to pay you a fee for the use of your code.
No liberal open source license can prevent commercial use of your product, without payment. If you really want payment, you should dual license your code, with a restrictive open source licence such as GPL and a commercial license that removes those restrictions on the payment of a fee.
Glen is right: if you use GPL, a commercial company can use your code but they have to open their changes to your code, which they may not be willing to do: so instead they'll contact you and pay for a commercial license.
Yes, it does matter which license you choose. If you don't specify a licence then by defaults all your rights are reserved, and no one will use your code (except dishonest people who don't care about licenses anyways). So if you want your code to gain visibility it's important to use an open-source or free license.
You could also go for a commercial license only. This makes sure no one can use your code (legally) without paying you, but you also run the risk that no one will bother.
The license is only part of the process. First you need to think of a business model. What is the value that a potential customer is willing to pay for. You can offer services, training, consulting, additional plug-ins/modules/features etc.
Depending on this analysis you then can look which license fits the best into your business model. That might be a dual license, might be only one. If your business model works better with your software being distributed widely, a more liberal license works probably better, and so on.
Hope this helps a little!
Is your code really that good / worthwhile to go to all the effort? My advice would be that unless you have a truly awesome & polished product, pick a liberal license and add a paypal donation button on the website. If your code is popular you'll get extra kudos, and there are still possibilities for making money in the long term.
This may be a reflection of my own personal projects more than anything, but even so - I'd caution against getting all excited about selling your code until you know there's a market for it.
One option is to make the software freely available, and provide a consulting/support service for your software. Businesses may want your expertise in configuring or extending the software, or providing support when things go wrong.
This of course depends on what sort of software it is.