Subject: Re: Reviews for lisp implementations From: Erik Naggum <erik@naggum.no> Date: 1999/04/15 Newsgroups: comp.lang.lisp Message-ID: <3133160386747264@naggum.no> * Arthur Lemmens <lemmens@simplex.nl> | I've waited two days for people with more experience to shed some | light here. But, apparently, nobody is willing to burn his fingers | on a comparison between Harlequin and Franz. that's because this is the kind of stuff lawsuits are made of. you need a protective wrapper of serious legal quality to dive into this matter of comparing products in general. not that I think Franz or Harlequin will sue anyone, but most professionals are aware of the problems of comparing products, and consequently avoid it, at least in public. | So here's my (very personal and very subjective) impression, based on | about 1000 hours of working with Harlequin's Lispworks, 50 hours of | experiments with Franz' previous version (don't remember version number) | for Windows and about 5 hours of playing with Franz' current version. | All of this on Windows 95/98. although extremely important to inform your readers of (thanks), this makes your comparison "weak". (I wouldn't be able to provide a stronger comparison, by the way.) | * Price price comparisons are more dangerous than any other comparisons. | * Conformance to standards. this comparison should be performed by someone very familiar with the standard and its semantics, because impressions of non-conformance may actually be within the bounds of conformance, and some non-conformances may be insignificant and easily fixed if the vendor is alerted to them. | My impression is that both companies are pretty good at conforming to the | ANSI spec, but that Harlequin takes it a bit more seriously than Franz. this is _very_ difficult to establish from watching the products, as it refers to intentions and future, not to the past. it _is_ fair to say that Harlequin's LispWorks conforms better to the specification in some areas than Franz's Allegro CL does, but it has to be an area-by-area comparison to be fair, and the severity of the non-conformance is also important for a fair comparison. e.g., _my_ impression is that Allegro CL has a weaker safe mode (not all errors signal errors as they should) than one could hope for, but this is not an area where I need it, so it may or may not matter to a particular programmer. (incidentally, I know that Franz Inc _is_ taking conformance seriously and I'm working with them to help us all get there.) | Harlequin seems to be much better at supporting Unicode and other | character sets. although very valuable for a user, this is not about conformance to the ANSI Common Lisp standard. it is therefore important to state what you expect from a product. | Franz still seems to think that 256 characters is more than enough (just | like Bill Gates thought that 640K is more than anyone would ever need). such parenthetical remarks, however, make your "comparison" nigh useless. incidentally, Franz Inc has an "international" (= Japanese) version that covers the need of most present non-Latin speakers. (I have had to do a little home-brewing to get ISO 8859-1 working as I want it to in Allegro CL, but I don't know whether LispWorks is any better.) | * Integration with underlying platform this is a valuable comment to a user. | * Performance comparisons here are fraught with danger and should be performed with published code and all sorts of things. e.g., some property that makes it feel "sluggish" could be extremely easy to fix, and other properties can be very hard to change because they are pandemic to the design. I think performance comparisons are _generally_ unfair, because after you have decided on a product, you learn how to make it faster. | I'll be happy to have my impressions corrected by people who know | better. I don't want to snap at you, but it's a _lot_ safer to talk to the person requesting a comparison and let it be a personal exchange, rather than post impressions and request correction; it usually requires a huge effort to correct simple misimpressions. this is why comparisons often produce a tremendous amount of noise on the newsgroups. also, most user impressions are exceedingly hard to quantify, and a lot of factors come into play. incidentally, I haven't had the opportunity to compare Allegro CL with much anything else. (I went from CMUCL 17f to Allegro CL 4.3 and it was a world of difference, so I don't even consider CMUCL possible to compare in the area I think matters the most: the development environment.) I get the performance I need, and I get the support I need from Franz Inc whenever I wonder about something or find a problem, and I see no reason to go look for a competing product. now, this is more an accident of history than anything else, so it does in no way preclude similar experiences with Harlequin -- it just didn't happen to me. my guess is that this is how most user impressions are formed: luck and good timing. #:Erik -- environmentalists are much too concerned with planet earth. their geocentric attitude prevents them from seeing the greater picture -- lots of planets are much worse off than earth is.