Capitalise the first letter of computer programs and applications (including web applications, add-ins, toolbars and extensions that can be added to applications), and follow manufacturer (or owner, if open source) usage:

Sometimes these names change with time. Mac OS X became OS X and then macOS. In general, choosing the current usage and providing adequate ancillary information (eg version numbers or names), if needed, gives a good balance between consistency of appearance and accuracy.

Capitalise the first letter of programming languages:

Remember that sometimes (eg for compatibility reasons) a version or range of versions must be indicated. Be as specific as necessary:

Protocols are written in lower case because they are essentially descriptions:

Names of established standards are rarely written out in full, but should follow the usual rules for capitalisation of international and national standards:

Note that unicode is short for universal coded character set (see Syllabic abbreviations, and is written in lower case unless in a formal title (referring to the Unicode Consortium or similar).

Some terms begin with a lower-case letter or number, and this cannot be changed because it is an important part of the name. Do not use these terms at the start of a sentence – recast the sentence if necessary:

In formal writing, do not use a program or command name as a verb: