Complex sentence: Two command line versions are provided: 7z.exe, using external libraries; and a standalone executable 7za.exe containing built-in modules, but with compression/decompression support limited to 7z, ZIP, gzip, bzip2, Z and tar formats.
Split into simpler sentences: Two command line versions are provided: 7z.exe, using external libraries; and a standalone executable 7za.exe containing built-in modules. However, 7za's compression/decompression support is limited to 7z, ZIP, gzip, bzip2, Z and tar formats.