I already wrote a post regarding a free tool for drawing sequence diagram by typing just text. But it lacked few features. Basically few days back, I was looking for some frame or boundary element that I can use to logically group some participants. I won’t say this requirement is part of standard UML sequence diagram elements. But it’s needed when you are working with too many objects. And sequence diagram will have more visual clarity if you can define few logical division between different subsystems.
sequencediagram.org came to the rescue. I even have Lucidchart account. But their sequence diagram markup language is pretty limited in option. Even my earlier post was better to draw a sequence diagram if you are planning to write some text & just get it done with (Obviously Lucidchart can do a lot more things than drawing a sequence diagram from input text).
So feel free to try this new one out & check the syntax for different options & features.