Jabber.org is an example of someone that did exactly what we did, which was take the MPL licence and modified it a bit. It is pretty common.
The chief reason we switched to a MPL-derived license was so that people could add to it and release it under any license they want. I've been in a room with a possible development partner and he immediately said GPL would be unworkable for many of his clients.
If you write a package for ACS 4.6, you can release it however you want...
The modifications requiring you to credit ArsDigita are pretty much what they seem. The product costs millions to build and it is an attempt to get some advertising in return for this investment.
Those are the high level points; please do check it out the licence and give us feedback, esp. if you deem it completely unworkable. We don't suspect this is the case.
This is the first version of ACS we've release that has been heavily load tested. We use to try to apply some load on photo.net, but that because increasingly unworkable and then some of our clients had loads that peaked higher than photo.net. There is nothing like expecting a bunch of load and having no idea what the server can take (an experience I've had a few times and it was not fun, so I'm very glad we have the testing facility).
We are testing each release and working through issue at a time. Publically stating what we have found is our attempt at getting better about describing where the software is and what to expect. This is the starting point, and you will see
regular releases with bug fixes and other improvements from here.
You'll find the architectures of TCL verses Java very different.
So yes, the systems are clearly different as Don pointed and may support different needs depending on what you want. So, in that respect, we (ArsDigita) and I (because I wrote a lot of it:) are pysched to see the TCL version go on strong.
