RailoLicense - getrailo/railo GitHub Wiki
What licence does Railo use?
Railo uses the GNU Lesser General Public licence version 2.1 or as it is more commonly known, LGPL v2.1.
I'm not a lawyer, please explain LGPL
There is a pretty good explanation here and even why you shouldn't use the LGPL. The 4cff.org also has an excellent PDF explaining licensing in general.
##TL;DR
Can I host a non-commercial or a commercial website using Railo?
Yes!
Can I provide non-commercial or commercial hosting using Railo?
Yes!
Can I create my own Railo installer for non-commercial or commercial purposes?
Yes!
Can I include Railo on a CD / DVD / BluRay Media?
Yes!
Can I embed Railo in my non-commercial or commercial application?
Yes, provided that you've left the licence and source intact.
Can I modify the source of Railo?
If you modified the source, you must provide us a patch of what was modified.
How does Railo make money or stay in business?
Railo Technologies offers: Paid Extensions (cluster scope, cfvideo and more!), Professional services, Support contracts with full SLA Training.