On Tue, Sep 02, 2003 at 09:24:11AM +0200, Philip Newton wrote: [re RAR]
>I'm told it's fairly popular in (some?) Usenet binary newsgroups as a >standard way of distributing warez and moviez. ACE is another format that I understand is used in that context. >>From what I gather, it supports multi-volume archives natively (which >are a bit of a hack with the ZIP format); there also exists a PAR >scheme which gives parity information so if you miss up to 'n' segments >of a multi-segment file, you can recreate them from the parity data. Both correct, though I've never seen PAR actually produce a result. Actually, I've probably known about RAR for longer than most people; in 1994 I translated the documentation for RAR 1.40 from Russian to English, and uploaded it to Garbo. (Three weeks later, Yevgeniy Roshal brought out a new version with his own English translation, which was rather less comprehensible than mine, and didn't bother to answer my email.) >Compression is also sometimes better than with ZIP, possibly because of >one or both of (a) it's said to have a special "multimedia" mode that >is tuned to compressing audio and/or video (no idea how that works, >though) and (b) it can create "solid" archives (things .tar.gz - >compress the files as one rather than compressing each file >individually as in .zip, hence you can take advantage of redundancy >across files). Also both correct. Multimedia mode, AFAIR, looks for shorter repeated sequences than in text, because there's already been some compression done. RAR used to be practically guaranteed to be smaller than ZIP, but the format has got a bit bulky of late. Basically, it started as state-of-the-art compression code of 1994 and has been updated somewhat since, whereas ZIP is state-of-the-art for early 1992 and basically hasn't changed at all (RAR has now had four or five changes to the file format). In my experience, people who really care about compressed file size and are moderately technically savvy tend to use RAR or ACE; people who want their files to be readable by everybody use ZIP; people who are catering for virus-prone fools use self-installing EXE. (All of this only applies to the Windows world, obviously; I think the parallels in Unix, or at least Linux, would be .tar.bz2, .tar.gz, and dodgy commercial software with auto-extracting installers like the JRE.) Incidentally, I can highly recommend PowerArchiver, even though it's now gone shareware. It's the only archive extractor I use on Windows. >I've very rarely come across a file I wanted that was in .RAR format, >though. When I started computing in the 90's on PCs, it was LZH at the >beginning, replaced by ARJ shortly after I started; now it's ZIP. (And, >of course, the perennial .tar.Z / .tar.gz in the *nix world, though >.tar.bz2 are starting to show up in a couple of places.) For a while, ARJ was looking set to displace ZIP v2; it was producing consistently smaller files, and had just grown a solid mode (which originated with HPack, but that's another story entirely). But Rob Jung insisted on keeping the source entirely closed, which meant that instead of competing with ZIP as the "universal and featureful" format it was competing with RAR as the "small" format, at which it failed. >This is probably not relevant >for whoever started the thread, though. Neither is anything I've said here. R
