Bluefish is a powerful editor targeted towards programmers and web developers, with many options to write websites, scripts and programming code. Bluefish supports a wide variety of programming and markup languages and has many features, e.g.

- Customizable code folding, auto indenting and completion - Support for remote files operation over FTP, SFTP, HTTPS, WebDAV, etc. - Site upload and download - Powerful search and replace engine - Customizable integration of external programs such as lint, make, etc - Snippets plugin to automate often used code - Code-aware in-line spell checking - Zencoding or Emmet support - Bookmarks panel

but is still lightweight and fast.

This package contains the plugins. You will need it for the HTML dialogs, snippets, charmaps etc. So it's basically necessary.