Agreed. Well, with the date, anyway ;-) (though I am an SBCL user) Somewhere around 2000 we saw the end of AI winter. This most likely owes something to the fairly impressive Lisp marketing that PG did. Within a few years, several new Lisp books came out, and a few years after that we saw what the other poster mentioned: but not Just Clojure, a plethora of Lisps. To mention just a few: Clojure, Liskell, and LFE (LFE was actually started in 2007, first released in 2008). To the best of my knowledge all of these were completely unknown to each other at the time of their inception, and thus indicative of probable momentum in the wider Lisp community from an earlier time, possibly the once-again-growing acceptance of Lisp that started ~2000.
Then LispWorks was fully ported to Mac OS X (incl. Cocoa-based GUI and IDE) and there was then a replacement for Macintosh Common Lisp, which was given up and not ported to OSX/x86/Cocoa.
On the other hand, 1999 was the downfall of LISP in the statistical community because that's when Luke Tierney decided to stop working on LISP-STAT, a LISP dialect with extensions for statistics that was semi-popular before the advent of R. While there have been statistical systems based on LISP since (such as Incanter for Clojure and a port of many of the extensions of LISP-STAT to Common Lisp) none have managed to make a dent against R, unfortunately.
Users of maths software usually don't want to use Lisp syntax and are not ready to work in Lisp.
XLisp-Stat had also the problem that it used its own Lisp implementation, based on XLisp (upto Xlisp 2), which itself wasn't going anywhere. David Betz, the original author of Xlisp, rewrote Xlisp as a form of Scheme (Xlisp 3.0) and it died eventually. Xlisp-Plus, another Xlisp version, was mostly abandoned also in that timeframe - though there are updated versions available now.
Other math software, which had been ported to Common Lisp, is still maintained - like Maxima. The maintainers can concentrate on the application and the code is much easier portable to new systems because of a choice of implementations.
Had XLisp-Stat been fully ported to Common Lisp (actually a rough port of the Xlisp-Stat core to Common Lisp was done many years ago) and maintained there - at least the code would still be easier usable.
Having used early versions of Mathematica in university, I'm actually a huge fan of Maxima (a fork of Macsyma, the latter having been the principle inspiration behind Mathematica). I have it installed on several systems and use it now for all the things I used to use Mathematica. In fact, the CL source code for rational numbers in Maxima formed the basis of similar work in LFE (the horatio project).
I was very sad to find out that Xlisp-Stat had not been ported and maintained in CL :-/ ... perhaps a good project for a motivated, if fringe, *SoC project :-)
Sadly, I am old enough to agree with this assertion. I went from SBCL to ECL at one point looking for a small Lisp t embed or make games with, purely a hobby. I have not left the Lisp renaissance since!
