Here's reflate that is compatible with Inno Setup, it shows correct progress during decompression (optional), very few bugs with it. This does not deploy a large number of files during decompression so that a bonus.
Compression files:
rawdet.exe
reflate.exe
Decompression files:
raw2hif.exe
reflate.exe
Compression command line:
reflate -process input output
Decompression command lines:
reflate -restore input output
reflate -restore - - //for stdin and stdout
Arc.ini
Code:
[External compressor:reflate]
header = 0
packcmd = reflate -process $$arcdatafile$$.tmp $$arcpackedfile$$.tmp
unpackcmd = reflate -restore - - <stdin> <stdout>