[erlang-questions] A PropEr announcement

James Churchman jameschurchman@REDACTED
Thu Jun 16 14:48:15 CEST 2011

Part 1)

Ok better still, if the PropEr team really do feel that this is the kind of project that would benefit from begin gpl licences ( it's not... tho i can see the benefits for something like the linux kernel of being gpl ) then if i understand correctly to fix all theses problems all they need to do is :

The interface module & the macro header to PropEr needs to be dual licensed, 

All the clever code that does all the property testing can still be put as gpl.

Part 2)

To ask the wider question, is the worry of some commercial company grabbing the source and making a heavily modified close source version that is better, then attempting to *sell it*, really an issue:

There *already was* a closed source version, called "QuickCheck" and this got, in its near entirety, fully cloned, and in a relatively short space of time. I really cant see a few additions made by some unknown erlang company ever working :

A) There are not that many companies that know erlang well enough:
>> Even if for some unknown reason erlang solutions tried to do this, not that they would, there are still enough erlang coders out in the world to look at the version being sold, and to very very very very very very rapidly, if the additions are good, clone them again.. as i said before the entirety of PropEr is a clone to start with
>> There is no other erlang company that has even 50 % of the erlang talent, even dare i say erricson ? so not other company could even come close..

B) The additions made to PropEr are unlikely to be so substantial that people would pay thousands for these additions...

C) What any company would really pay for is the commercial support, the brains to produce very *good* tests, training, and if they really needed their own additions to the property based testing tool, these to be written by the people who know along with a lot more, none of which is the tool its self, but the brains who *understand* the tool
In *all* these cases they would go to QuviQ to have them do it, not to some odd startup that has a mildly bastardised PropEr that they refuse to open source

In this case ( and not the case of say linux etc..) i can only see the gpl getting in the way of the very purpose of the tool, and think that in the long run there will be a total NEED for the erlang community to produce a testing tool that is truly "free". "triq" should be possible to "trick" out, as it is apache 2, everybody can comfortably contribute, has the basic underpinning, and would be worth the effort in the medium, and definitely long term, to everybody.


On 16 Jun 2011, at 13:10, James Churchman wrote:

>> Magical Things Happen. The tendency for linking to GPL works being
>> required to be GPL works is a complicated thing that gets contested in
>> different ways in different places.
> hey amy, thanks for your reply
>> Making an intermediate API to present a non-GPL interface to
>> proprietary code is a pretty well established technique. See: some
>> video card drivers in Linux, with having a GPL compatible bit that
>> just creates an interface for the non-GPL compatible bits to later
>> use.
> well then, an intermediate (mit+gpl) module, lets call it "prop", fixes all the issues then :-)
> add in a few cleanroom macros and that sounds like an hour long job! anybody willing?
> ...no need to panic guys... :-)
> James
>> Making an identical API to an existing GPL based API also complicates things.
>> From here, the only correct answer is "Consult a lawyer in your
>> jurisdiction." Unfortunate, but that's how it goes.

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