Free high compression ratio software for windows

TC is an experimental command-line file compressor with fast decompression speed. It uses a ROLZ like compression engine.
Main features:
- High compression ratio
- Fast decompression speed (~4...15 MB/sec)

Ratio is a nice tool for command line usage that will tell you compression ratio computation.
As input it receives the list of files and produces a column of compression ratios.
The first file in a list is the reference file, others are test files.
Output numbers are compression ratios between reference file and each test file.
Reference file and at least one test file should be specified.
Options:
--help (-h) Display this information
--version (-v) Display program version
--reference (-R) Reference file
--test (-T) Test file
--show-reference (-r) Use reference file as test file
--show-name (-n) Display file name
--show-size (-s) Display file size
--kb (-k)
--mb (-m)
--gb (-g) Display file size in KB, MB, GB
--percent (-p) Display percent instead of ratio
--precision Precision value
Example:
> ratio sample.doc sample.zip
6.04

A small tool for compressing HTML files. It compresses all HTML files in a given folder. UnderPressure reaches an compression-ratio about 20%.

tacmp02 demo is a powerfull wav compression toolgiving virtually lossless comprressionin 1:3 to 1:5 compression ratios.it also works as a free demo of the powerfull taccompression , which plays the compressedfiles (tac files) and has provision for highercompression ratios (up to 1:15) whilemaintaining high audio quality.