Cadifra UML Editor is a fast and lightweight UML diagram editor for Windows 2000 and XP.

Supports Unified Modeling Language Class, Object, Use Case, State and Sequence diagrams.

Can reliably embed diagrams in Microsoft Word (and others).

Unlimited undo/redo without exceptions (limited only by memory).

Produces high quality diagrams (no arrows piercing boxes) while still very easy to use.

Implements full Windows Drag&Drop (drag a selection into Word to embed it or place a snippet onto the desktop.

Control+drag to copy something into same or another diagram).

No code generation.

No reverse engineering.

Intelligent handling of connectors, but not "too" intelligent (user can always position every segment where he/she wants).

Has a style editor to set fonts of text of families of UML elements (uses inheritance).

No pop-up dialogs to edit text (just double click on any text to edit it).

Stores diagrams in human-readable XML (Schema is fully documented).

Unrestricted free evaluation available for downloading (no questions asked - just prints a small eval notice on exported or printed diagrams).

Eval is only 1 MB to download.

No admin login required to install.

Cleanly uninstalls (uses Windows Installer).