Komodo’s customizable language-aware editor and extensible workspace assist the developer with a supportive yet powerful environment, including source code control integration (CVS, Perforce, and Subversion), web technologies support (CGI, XML, and XSLT), a powerful regular expression toolkit, and comprehensive debugging support.

Here are some key features of “Komodo”:
– Vi emulation: Modal keybindings which emulate the navigation, text insertion and command behavior of Vi. Custom commands can be implemented by adding Komodo macros to a Vi Commands Toolbox folder.
– HTTP Inspector: An interface for examining HTTP requests and responses as they happen. It runs a local proxy which intercepts HTTP traffic and records each transaction, which can then be viewed. The Inspector can break on a request or response, which can then be edited and submitted or re-submitted in its modified form.
– SFTP and SCP: Komodo now supports access to remote files via SFTP and SCP. Saved password information for all remote servers is stored securely in Mozilla’s native password manager.
– JavaScript Debugging: Komodo now offers JavaScript debugging using the Firefox web browser and the JavaScript DBGP extension. With the extension enabled, loading JavaScript or triggering JavaScript controls in the browser window opens a debugging session in Komodo, which loads the relevant JavaScript code.
– JavaScript Interactive Shell: An interactive shell for manipulating JavaScript code is now available within JavaScript debugging sessions. This shell is similar in functionality to the other interactive shells in Komodo.
– Redesigned Code Intelligence system: reimplementation of PHP, Python, Perl, Ruby, JavaScript, XML and CSS support. The Code Intelligence system is the backend for many of Komodo’s features, such as Autocompletion, Calltips and the code browser.
– PHP “Zero Configuration”: improved automatic configuration for PHP debugging.
– Live Folders: Komodo projects now offer Live Folders which display current filesystem contents. The previous folder behavior is still available; these folders are now referred to as “Virtual Folders” in the documentation.
– Live Import: Projects can now automatically act as a Live Folder; importing, displaying and updating the contents of the base directory specified when it is created. Project-specific Directory Import preferences define which files and directories to include. New projects use Live Import by default.
– Project Settings: All project settings are now moved to the Project Properties dialog. This dialog box is now used for files, folders and projects, displaying the appropriate properties for each type.

Additional Project functionality, including:
– Project based debugger preferences
– Basic file management (Delete, Rename, Show in File Manager)
– Project import from remote file systems
– New File option
– XML/HTML Autocomplete and CallTips: Komodo now supports AutoComplete and CallTips support for XML and HTML based on DTD or RelaxNG Schema. SGML and XML Catalogs are supported. The file being edited should contain a DOCTYPE declaration or a namespace in the root element, otherwise, only the current file data is used for completion.
– DOM Viewer: A new tab in the Project Pane (left) shows the DOM structure of XML and HTML documents in a tree view. Double-clicking on a node in the DOM Viewer moves the cursor to the corresponding node in the document.
– Help Browser: Komodo now uses Mozilla’s help browser for displaying Komodo help.
– New languages: Support for Template-Toolkit, HTML-Mason, Smarty, Django, and Luddite has been added using UDL
– User-Defined Languages: Komodo 4 introduces a system for adding custom language support called UDL (User-Defined Languages) which allows Komodo to properly syntax-color multi-language files and templated files common in many web programming frameworks. For this release, Komodo includes better support for RHTML using this system. More multi-language files will follow in subsequent releases. Also included is a tool called Luddite which you can use to define custom language syntax-coloring and package those into Komodo extensions.
– Project Templates: Projects templates can be created and used when creating a new project.
– SCC History: A new option has been added to the Source Control menu which displays the revision history of a file. You can compare (diff) two selected revisions from the list, or select one and compare it to the local copy.