Phix is open source. You can do pretty much anything you like with it, except:
  • Ship a closed source version of it or vary the availability of any part, original or additional.
  • Publish a "cut down" version unless you also provide a clearly visible link to a "complete" version.
  • Prohibit the inclusion of any modifications/ideas to Phix into future releases by any other party.
  • Object in any way other than meaningful and civilised debate should they be or not be incorporated.
  • Delete or obscure any author or origin details, or otherwise falsely claim any part as your own work.
  • Make malicious changes of any kind, including any intended to defame or discredit either author or product.
  • Implicate the product in any activity deemed illegal under current UK law, irrespective of your location.
You may sell a modified version of Phix, as long as you do not give away part of it. The source and binaries of the compiler itself are deemed "as one" and cannot be sold or given away separately. A reasonable "cut down" version might exclude all the non-essential demo\bench\test\doc\sfx stuff, but if the compiler sources are omitted they must be readily available elsewhere. Should you publish a modified version of Phix you automatically grant an absolute right to all interested parties to freely plagiarise or reverse engineer any useful features. Such rights do not extend to products or features unrelated to the compilation, interpretation, debugging, analysis, or production of plain text source code that just happen to be written in Phix.

The compiler itself is released under the strongly copyleft Open Software License version 3.0 whereby any derivative work must be afforded the same rights (source code etc) as the original work, while the run-time and library components, along with all demo programs, are released under it’s much more permissive companion the Academic Free License version 3.0 which is non-copyleft and allows use of those items in commercial closed source proprietary applications.