TextMate
TextMate is a general-purpose GUI text editor for macOS.
TextMate support in IntelliJ IDEA allows you to import bundles, matches IntelliJ IDEA and TextMate color schemes, and provides code completion in .markdown files.
Enable the plugin
Press Ctrl+Alt+S to open the IDE settings and select Plugins | Installed.
Select the checkbox next to the TextMate Bundles plugin.
Apply the changes and close the dialog. Restart the IDE if prompted.
Import TextMate bundles
IntelliJ IDEA allows you to work with TextMate bundles. You can download bundles yourself, for example, from GitHub, store them on your computer, and then import them into IntelliJ IDEA.
Suppose you want IntelliJ IDEA to highlight syntax of the OCaml files.
Download the OCaml TextMate Bundle. It now resides on your hard disk.
Press Ctrl+Alt+S to open the IDE settings and select Editor | TextMate Bundles.
Click and locate the OCaml bundle on your disk. It appears in the list of recognized bundles:
Test the imported bundles
Once a TextMate bundle is added, IntelliJ IDEA provides syntax highlighting for the file types registered with the bundle. Here's a sample OCaml code fragment that uses the TextMate bundle we've added earlier: