I wrote a while back about my struggles opening .docx files. Though not exactly obscure, they were new at the time and presented an unnecessary headache when all I wanted to do was read the document. Today I was presented with another new-to-me file extension: .hqx
Some other people who also received the document complained about being unable to open the file (so suddenly I became interested in what might be inside, motivating me to open my mail too). A little experimenting has shown that Open Office opens the file quite nicely, with all formatting preserved. Textpad was also able to open it although in text-only (naturally) so the fancy indenting and emphasis, etc were stripped.
For those interested in the details, .hqx is the file extension for BinHex encoded files. From Wikipedia:
BinHex, short for “binary-to-hexadecimal”, is a binary-to-text encoding system that was used on the Mac OS for sending binary files through e-mail. It is similar to Uuencode, but combined both “forks” of the Mac file system together, along with extended file information. BinHexed files take up more space than the original files, but are far less likely to be corrupted in transit.
In other words, it’s a Mac thing.