An update is planned for the Files app for Chrome OS in October, adding support for additional archive file formats.
Zipping and Unzipping Files on a Chromebook
9to5Google reports that the Chrome OS Files app will support additional archive file formats in a new update scheduled for release in October. While the lack of support hasn't stopped users from opening specific files (other apps can do that), being able to open most archived files with a single app would be more convenient.
According to a post on Chromium Gerrit, the added formats include 7z, bz2, crx, gz, iso, tar, tbz, and tbz2. As 9to5Google points out, there is some interesting potential in some of these file formats, as they each serve a different purpose. For example, .crx files are used to archive official Chrome extensions, while .iso files have been used to archive operating systems.
Tape Archive (.tar) files are commonly used to combine multiple files into a single file for Linux and Unix systems. BZIP2 Compressed (.bz2) files are commonly used to compress file containers that normally cannot be compressed and are typically only used with Unix-based systems. BZIP Compressed Tar Archive (.tbz and .tbz2) files are a combination of the .tar and .bz2 formats that use BZIP2 to compress archived TAR files.