IPF and Openness

[pak21]

i beleive i'm right in what i'm saying, please correct me where i'm wrong.

That's pretty much it. Of course, if someone else writes a GPL-compatible IPF library, then it doesn't necessarily having to be under the GPL itself: it could be under a very liberal license like the MIT 2 clause license, which would make it available to the commercial users you are hoping to sell to.

[IFW]

btw: Anyone expert on licensing please do feel free to PM or a send an email directly if too shy to post publically

[IFW]

Ok, so maybe we are getting somewhere...
Again, what's up with MAME's licence? The project source and derivatives are widely available, as far as I can see no one has any issue with its licensing and afaik it should cover our bases.
Also what are/are there any GPL-compatible licences that would work for us?

Thanks.

[Interceptor]

i beleive i'm right in what i'm saying, please correct me where i'm wrong.

That's pretty much it. Of course, if someone else writes a GPL-compatible IPF library, then it doesn't necessarily having to be under the GPL itself: it could be under a very liberal license like the MIT 2 clause license, which would make it available to the commercial users you are hoping to sell to.

okay i'm being thick here maybe.

so there is a GPL *compatible* license, that isnt GPL, but GPL allows you to link to it?

i had figured it was GPL for GPL and thats it. where is the definition of compatibility? has that already been mentioned? sorry if it has, i have trouble ingesting a lot of this...

[Interceptor]

okay i missed a bit a few posts up. sorry.

[Interceptor]

and now for this important message:

this isnt about IF we open it up, we are opening it up, this is about HOW.

WHEN is as soon as we get a workable solution. ideally, we want one today, or this week, the only delay is working it out and trying to suit everyone.

[Tuxie]

Here is a list of licenses proven to be compatible with the GPL: http://www.gnu.org/licenses/license-list.html

Also consider dual-licensing. You can release the library as GPL AND some other license. A library under GPL can only be linked with GPL software but GPL software can link to libraries of any GPL-compatble license in that list. Those wanting to legally use your library to make money are very unlikely to GPL their software to do so. Those who don't care about legality will use it regardless of which license you choose.

A reasonable (IMHO) solution is to dual license it with the GPL and the MAME license:
http://en.wikipedia.org/wiki/MAME#MAME_license

[IFW]

Isn't it incompatible with GPL, to dual-license something? I thought so by pak21's quote.

[pak21]

Again, what's up with MAME's licence?

The MAME license is intended for a complete program, not for a library. With my black hat on...

* I create my commercial emulator. In this, I create an interface to the IPF library API. I also create a library which implements the IPF library API, but reads EDSK files instead of IPF files.
* I ship my emulator with the EDSK library.
* I let it become known that if users replace the stub library with the official IPF library, they'll suddenly get IPF support.

Or in other words, can you copyright an API? That'll need a lawyer to answer.

[ Edit: fix formatting ]

[pak21]

Isn't it incompatible with GPL, to dual-license something? I thought so by pak21's quote.

Yes. You're perfectly allowed to dual-license things under incompatible licenses - in fact, this is the entire reason you do it - if the licenses are mutally compatible, then there's no point.

However... this probably isn't going to have the effect you want. Any commercial users will simply be able to use the library under the GPL; non-commercial users would have the option of using either the MAME license or the GPL.