What are some alternatives?
When comparing p7zip and B1 Free Archiver, you can also consider the following products
WinRAR - WinRAR is a powerful archive manager.
PeaZip - Free file archiver utility, free Rar files software. Open, extract 7Z ACE CAB RAR TAR ZIP archives, support 180+ formats. Data compression and encryption tool.
Bandizip - Bandizip : All-In-One Free Zip Archiver. Bandizip is a lightweight, fast and free All-In-One Zip Archiver.
File Roller - File Roller is an archive manager for the GNOME desktop environment.
WinZip - The world's best file compressor in the world.
The Unarchiver - Get the top application for archives on Mac. It's a RAR extractor, it allows you to unzip files, and works with dozens of other formats.