B1 Free Archiver is a straightforward open-source archive manager for Windows, Mac, Linux and Android.
The program opens a good range of formats - zip, zipx, 7z, rar, tar, iso, cab, jar, qz, bz2, arj, deb and lzh on Windows, an impressive 37 on Android - although it only creates archives in zip and its own b1 format.
Archives can be split as they're created, or password-protected with 256-bit AES encryption. You also get various compression modes to help you find the right balance between speed and performance (Store, Smart, Classic, Maximum, Ultra).
The B1 Free Archiver interface is clear and straightforward. A simple Explorer-type view makes it easy to find the files you need. A Preview window displays the contents of some documents. The core options are a click or two away on the toolbar (Create, Open, Extract), and there are some handy extras in the menus (test your archive, display the current folder in an Explorer window, open a command prompt there).
There's also an unusually wide choice of default "open" actions. Double-click an archive and you can have it open in the full program, a simple version with just the core options (view, extract to various folders), always extract and prompt for a folder name, or extract immediately without any prompts at all (your files will be extracted to a new folder with the archive's name).
It's not the most powerful of archive tools, but B1 Free Archiver's ease of use and ability to run just about anywhere ensure the program still has plenty of appeal.