Microsoft Open-Sources Command-Line Editor Edit 2.0: Supports Syntax Highlighting and is Under 300KB
Microsoft's command-line text editor Edit, open-sourced last year, has received a 2.0.0 update, adding syntax highlighting. The Linux version is only 294KB in size. The biggest change in Edit 2.0 is the addition of syntax highlighting support, covering a variety of languages such as plain text, Diff, GitHub Commit/Rebase, Ignore, JavaScript, JSON, LSH, Markdown, PowerShell, Properties, Python, Shell, Script, XML, and YAML.

This feature adds only about 40KB in size, and you can switch highlighting languages by clicking XML in the lower left corner.
Other updates include: find and replace supporting regular expression capture groups ($1, etc.), new editing enhancements such as moving lines and batch indentation, file lists changed to natural sorting, preliminary support for settings.json configuration files, and fixes for numerous Unicode and cross-platform related issues.
Edit's core positioning is as a lightweight terminal editor, and its support for mouse operation is its biggest feature, making it more user-friendly for those unfamiliar with Vim keybindings.
Edit supports Windows, Linux, and macOS platforms, but the Windows version is nearly 2MB in size, a significant difference from the Linux version's 294KB.