PAQ and LPAQ are two
families of experimental compressors developed by Matt Mahomey and
contributors (
PAQ
and LPAQ 
project page).
PAQ compression
has high computational requirements (memory, CPU time) if compared to
mainstream compressors, but reaches the highest compression ratio
presently possible.
Most of
top
ranking compression algorithms belongs from PAQ family
or are
derived works like ones featured in KGB
Archiver, WinUDA, WinRK and Emilcont.
LPAQ is a "lite"
version of PAQ, meant to be faster but providing lower compression
levels; it is a compression only utility, so LPAQ-compressed files will
feature a double extension, i.e. filename.ext.lpaq.
In PeaZip if multiple files are sent to be compressed by LPAQ they will
be automatically added to a TAR archive before, resulting in the doule
extension TAR.LPAQ.
Both PAQ and LPAQ, due to the experimental nature of the project,
doesn't feature backward compatibility, so archives created with a
PAQ/LPAQ version need to be extracted with the same version.
PeaZip offers a GUI frontend to
create,
browse and extract many PAQ (PAQ8F, JD, L and O) and LPAQ (LPAQ1
and LPAQ5) archive types, under Windows
and Linux (on Gnome, KDE or other desktop environments).
To extract a PAQ or LPAQ file you can:
- Use context menu entry "- Extract archive(s) here"
- Use context menu entry "- Extract archive(s) to" to
be asked for output path
- Open it in PeaZip and use
"Extract all" button (you can chose output path in "I/O" tab) or
"Extract all to" to be asked for output path.
