The 'fs_pack_vpk' allows compressing specific files into a VPK (compressed). This implementation has better compression ratio's then currently available VPK tools with compression (at the cost of speed).
The implementation is early, a directory iterator with a files for flags is planned soon to fully rebuild VPK's on-demand. A dedicated standalone program is also planned.
The output dir and archive formats should match 1:1 with the original game