Do you have a detailed change log?

Yes.

Is there a SubEthaEdit for macOS earlier than macOS High Sierra (10.13)?

The latest version to support as low as OS X El Capitan (10.11) is 5.0.2 and can be downloaded from through these links:

• SubEthaEdit 5.0.2 (SubEthaEdit.net).
• SubEthaEdit 5.0.2 (GitHub Releases Page).

How can I open a hidden file with SubEthaEdit? E.g. ~/.bash_profile

There are two ways of doing so:

• In the open dialogue in the bottom left, there is an options button. When pressed it exposes some options for the open dialogue. Enable: "Show hidden files" for hidden files to show up.
• Install the see command line tool – instructions can be found in the Advanced Preferences. After that just use it in the terminal. E.g. see ~/.bash_profile

Isn't "SubEthaEdit" a really silly name?

Probably. However the name has been chosen to honor one of the greatest visionaries of computer supported collaborative writing, Douglas Adams, author of "The Hitchhiker's Guide to the Galaxy", one of the funniest and greatest books on earth. In his books he envisioned a travel guide for aliens, which was updated by multiple editors collaborating over the "SubEthaNet". SubEthaEdit is pronounced Sub-Etha-Edit. Sub like in "Subway", Etha like in "Ether", and Edit like in "Editor". In a previous life, before a trademark dispute, SubEthaEdit was called "Hydra".

How do regular expressions work?

Have a look at "Help → Regular Expressions" for a summary of SubEthaEdit's regular expression vocabulary. To learn about basic and advanced regular expressions we recommend regular-expressions.info.