When comparing WebSequenceDiagrams vs PlantUml, the Slant community recommends PlantUml for most people. In the question“What is the fastest way to create and edit UML diagrams?” PlantUml is ranked 1st while WebSequenceDiagrams is ranked 14th. The most important reason people chose PlantUml is:
For example from Emacs, Sublime Text and so on. You can learn about integrations [here](http://plantuml.com/running).
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Uses simple language and syntax
Pro Web based UI
No need for installation
Pro Many, many integrations
For example from Emacs, Sublime Text and so on. You can learn about integrations here.
Pro Easy create diagrams from text
There is even a Visual Basic Macro to draw UML diagrams in Word.
Pro Free/libre/open source (GPL)
Source code can be browsed here.
Pro Has online editors
Such as.
Pro sphinx-contrib extension for embedding into docs
sphinx-contrib extension on PyPi
Allows you to keep your UML definitions under VCS and include them inside generated documentation with ease.
Cons
Con Not free
Image quality requires a fee and other features.
Con The "plantUML-language" is a bit strange and hard to grasp for new people
Con Slow development due to it being mostly a one-man project
There’s been no recent contribution to the source forge project but from the administrator arnaud_roques. Future contribution might be difficult due to lacking code documentation.