Opinions on Unladen Swallow?

I have high hopes for it.

1. This is being worked on by several people from Google. Seeing as how the BDFL is also employed there, this is a positive.

2. Off the bat, they state that this is a branch, and not a fork. As such, it's within the realm of possibility that this will eventually get merged into trunk.

3. Most importantly, they have a working version. They're using a version of unladen swallow right now for Youtube stuff.

They seem to have their shit together. They have a relatively detailed plan for a project at this stage, and they have a list of tests they use to gauge performance improvements and regressions.

I'm not holding my breath on GIL removal, but even if they never get around to that, the speed increases alone make it awesome.

I think the project has noble goals and with enough time (2-3 years), they will probably reach most of them.

They may not be able to merge their branch back into the trunk because Guido's current view is that cpython should be a reference implementation (ie. it shouldn't do things that are impossible for IronPython and jython to copy.) I've seen reports that this is what kept the cool parts of stackless from being merged into cpython.

This question discussed many of the same things. My opinion is that it sounds great, but I'm waiting to see what it looks like, and how long it takes to become stable.

I'm particularly concerned with compatibility with existing code and libraries, and how the library-writing community responds to it. Ultimately, aside from personal hobby projects, it's of zero value to me until it can run all my third-party libraries.

Guido just posted an article to his twitter account that is an update to the Jesse Noller article posted earlier. http://jessenoller.com/2010/01/06/unladen-swallow-python-3s-best-feature/. Sounds like they are moving ahead as previously mentioned with python 3.