Look at the "License" part.
"The JDL allows commercial use of vecmath with or without modification, as long as compatibility with the entire API Specification is maintained."
This is what I meant. I am not sure if Kenji Hiranabe vecmath will pass _ALL_
TCK tests (say, serialization).
TCK is "Technology Compatibility Kit", set of tests to run against API implementation to ensure it is compatible. In some cases it is trivial ckecking of all method signatures defined in API, in some cases - much more deeper testing... say, I did not check the TCK for vecmath, so I can not say if that lib will pass it.
Another point that somebody (me?) has to SIGN the JDL for vecmath.
(i) Source Code. You can only distribute source code for the RI and Modifications under all of the following conditions: (a) You make such
distribution under the terms of this JDL; (b) without offering or imposing any different terms; (c) to a receipient who has accepted the terms of this JDL;
and (d) You provide a copy of this JDL to each such receipient;
Means that source code of vecmath can not be distributed under BSD license
(ii) Binary Code. You can distribute binary code for the RI and Modifications but only under license terms which (a) have been accepted by the
receipient; (b) are consistent, and not conflicting, with the terms of the JDL; and (c) where such terms are no less protective of Sun than the terms of this
Means "you have to consult our lawers in order to ensure that your binary code license is "consistent, and not conflicting, with the terms of the JDL", and terms of it "are no less protective of Sun than the terms of this JDL", and better you have to get written confirmation from us.
Another consequent that "You have to enforce all who download your program to accept terms of your binary license".
It is only possible to get TCK after signing this agreement (maybe I really shall do that... still thinking).
If Sun policy (as communicated to You by Sun) also requires verification of compatibility for Your Compatible Implementation then You
shall, prior to the FCS of the Compatible Implementation, submit verification of compatibility to Sun or to an independent test facility designated by Sun. If
such verification is by an independent test facility, then the reasonable costs of such activity (including any applicable fees) shall be at Your expense.
Means that before publishing the lib, Sun _MAY_ require you (or me - this is more realistic - if I wish to publish that lib) to pass certification at some software certification lab at our expence (which - you can be sure - can be not really cheap, because of "reasonable" means different for different people)...
I will treat this as "a kind of pushing (well, not so strong) commercial companies (like mine) to contribute to Sun-supported projects rather than publishing their own implementations of public Java APIs". This is not so bad in general if we think from strategy viewpoint, but there are different reasons to do or not to do something.