Binhex is a file format that takes both the data and resource forks of a mac file or directory, along with mac-specific meta-information such as file and creator type, and stuffs it into one single text file so that the forked data can be transferred over networks or onto drives with non-macintosh file systems that do not understand the concept of a fork.

Because binhex is a text file, it can safely be posted on usenet and other places that binary can't go. Because of this, it is seen a lot more than the corresponding MacBinary format even though it produces larger files. For example, if you ever attatch a mac file to an e-mail, your e-mail program is possibly transparently encoding that file as Binhex.

Binhex uses the .hqx file extension. If you need to open a .hqx file and you can't figure out how, try Stuffit Expander. I'm not sure how you would go about opening a binhex file in linux or another unix; i've never had to do it before.