Features of Common Lisp Abhishek Reddy used to have a page up on the topic, based on Robert Strandh's list. It's been down for a while now, so I rescued a copy from the Wayback Machine and put it up. So: Features of Common Lisp.
Reporting Bugs, Howto. I think it is actually a good thing that I need to say this, because it tends to be a sign of new people in the community, but if you've never read it, go now and read Simon Tatham's How to Report Bugs Effectively.
TL;DR. *sigh* Short version: provide directions to reproduce such that your idiot cousing could follow them while drunk. Don't be afraid of giving too much details. Don't speculate on causes.
- Use (lisp-implementation-version) to check the version of the Lisp you're actually running.
- Use "uname -a" to get information about the OS and architecture you're running on.
- When providing information, copy-paste as much as possible directly from the terminal or Emacs.
SBCL 1.0.54 due in a few days. This means we're in our monthly freeze, and testing is much appreciated. This month's release contains a lot of changes -- including plenty of threading work.
Microbench. A while ago I mentioned a microbenchmarking suite I'd been working on on-again, off-again. It's still not much to look at, and comes with zero documentation -- but curious souls can now get it from Github It should work on SBCL, CMUCL, CCL, and Lispworks. Clisp and ACL not tested yet, but a port should be fairly trivial.
What Microbench Is Good For, and Why You Should Not Trust Benchmarks at All. Look here. Pay special attention to double-sans-result+ and double-unsafe-sans-result+. When I published some of the results earlier, I was a bit surprised that they didn't perform much better then double+. Then I ran the same benchmarks on CCL and saw it running those two benchmarks 5 times faster!
With a bit of help from Paul Khuong the difference turned out to be SBCL's loading of floating-point constants, which is heavily optimized for inline-use. I have a pending patch that makes this smarter, whose effect you can at link see above.
The moral of "be sure what you're /really/ benchmarking" is an old one, but bears repeating. What makes microbenchmarks attractive to me, however -- despite their many shortcomings -- is that when something turns out slow (in comparison to another implementation, a previous version of SBCL, or another comparable benchmark operation) is tends to be easier to figure out the cause than with a macrobenchmark.
You probably also noticed that CCL seesm to do really badly at inline floating point arithmetic if my benchmarks are to be trusted. They're not. I'm 99% sure this is a case of the something specific in the way those benchmarks are implemented heavily pessimizing them for CCL.