I accidentally find Ken Silverman’s utility page from time to time and can never find it again when I want it, so if you need the ultimate command-line ZIP utility (KZIP), or the ultimate PNG optimizer (PNGOUT), to squeeze just as many bytes as possible out of your recompressed archives or your images while maintaining 100% compatibility, save this link. You’ll thank me later when you need it badly, like when you’re e-mailing an archive and it’s a few dozen bytes larger than your e-mail system allows.
Also check out his clever ZIPMIX utility.
What makes his approach to ZIP archiving special is that he emphasizes file size over speed. His software is built to take a few extra seconds to save a few bytes, if it’s possible to do so. Mainstream Zip/Unzip programs will still decompress his archives just fine; they just won’t match it for compression ratio most of the time. And in the rare event that they do, his ZIPMIX utility will take advantage of that. Just zip up the same files with both programs, then run ZIPMIX on the two archives. So Ken Silverman’s utilities win even when he loses.
I first noticed this phenomenon when using Info-Zip, when I found its -9 option produced smaller archives than PKzip’s -max option. The first thing I did was make sure PKzip could uncompress the Info-Zip archive I’d created. It did, so I never used PKzip to create an archive again. And every once in a while I find another tool that does better than the last best one I found. Right now Ken Silverman’s utilities are it.
I have an unusual appreciation of smaller archives. That’s because I’m old enough to have downloaded files over a 300-baud modem (but also young enough to remember having done so). Ken Silverman practices a lost art, and maybe there aren’t a lot of people left who appreciate that, but I still do.