XML Cooktop is a development environment for writing and testing XSLT style sheets, XML documents, DTDs, and XPATHs. It also features Jabber Instant Mesenger Client and peer-to-peer Cooktop Online Comunty for XSL developers.Features:
Extensible support for external tools, such as XSL processors, XML formatters, and web browsers
Color-Coded XML editing
Ability to open files via URL
Checks well-formedness and validates XML documents
Choice of XML parser to use for validation
Various text-entry short cuts -- see Help/Keyboard Map for a complete list
Extensible library of Code Bits, which are cataloged text fragments that can be inserted into any document and shared with other users. Code Bits can insert code around selected xml. For example, you can select some XML and insert xsl:for-each element around it.
XML Navigator - Ctrl+3
Spell checker (requires MS Word)
Automatically remembers the pairs of xml/xsl files used and can group them into files called "workspaces"
File Open dialog allows XML and XSL file to be opened at the same time via "multi select"
Custom file extensions for xml, xsl, and dtd files
"Bookmarks" let you mark lines in a document for easy identification
XPATH Support
Extraction of XML tags and XPATHs - Ctrl+2
XPATH testing and generation
Stylesheet testing
Displays generated HTML in browser window (integrated or external)
Support for multilevel XSL includes and imports
XSLT Run-Time Parameters
Document formatters and reports
XML Indenting
MS XSL to XSLT converter
Peer-to-peer features
Sharing of Code-Bits and Web Favorites
One-on-one chat and anonymous group chat
More to come
Integrated web browsing
Extensible library of XML and XSLT related resources on the net

XML Cooktop users can collaborate over the Internet in real time via Jabber. Cooktop can even be used as a simple Jabber chat client application.