I've been a user and fan of Komodo IDE since it was first introduced in 2001. Although newer products, such as Sublime Text and WebStorm, have surpassed it in some areas, it is still a very good editor and IDE.
Komodo IDE already had column editing; in 8.5, it added multiple selections. This provides near parity with Sublime Text as far as mass edits are concerned. As long as we're doing the comparison, Komodo is more of an IDE, and Sublime Text is much faster. And since we're discussing performance, Komodo's speed has improved noticeably compared to older versions, in screen drawing, search, and syntax checking.
Another differentiator is the database explorer, which lets you examine the structure and content of various databases. SQLite and Oracle support are built in. I installed a MySQL extension in a few minutes, and it worked well. Unfortunately, extensions for additional databases, such as Microsoft SQL Server and PostgreSQL, don't seem to be available. For this particular purpose, you either need to use a separate database client program or an integrated development system that knows about lots of different databases, such as Alpha Anywhere.
Collaboration is another Komodo IDE differentiator -- think Google Docs for code. You can create sessions for groups of files, add contacts to sessions as collaborators, then work together on the same files at the same time, with near-real-time synchronization.
Collaboration is not a replacement for source code control, but it's a useful supplement. Komodo IDE integrates source code control using CVS, Subversion, Perforce, Git, Mercurial, and Bazaar. Only the basic version control operations are supported. Advanced operations, such as branching, must be done using a separate source code control client.
Komodo IDE has a DOM viewer that lets you view XML and HTML documents as collapsible trees. It also lets you do XPath searches to filter the tree.
Komodo IDE can publish groups of files over FTP, SFTP, FTPS, or SCP. Komodo can also synchronize files and detect potential publishing conflicts that could cause you to overwrite other people's changes.