In the currently online documentation
(http://roundup-tracker.org/docs/customizing.html#templating-engines),
we state, " As of 1.4.20 Chameleon support is highly experimental and
not recommended for production use."

Now we have roundup 1.6.0, and I wonder whether this is still true.

I noticed there is a package z3c.pt which claims to provide full ZPT
compatibility, so we might be able to to switch to z3c.pt/chameleon
completely by default; the "chameleon" choice would be for templates
which use chameleon directly and are incompatible to ZPT.

Here is the full documentation of the differences from the official
chameleon documentation:

https://chameleon.readthedocs.io/en/latest/reference.html?highlight=differences#incompatibilities-and-differences

Since 1.4.20 no significant changes have been made here, so it probably
still is as experimental as back then.

I second that chameleon is still experimental, I don't think we even run
test cases using chameleon.