title: How to draw Message Sequence Charts?
body: <p>Is there a component (preferably free) to help me draw <a href="http://en.wikipedia.org/wiki/Message_Sequence_Chart" rel="nofollow noreferrer">Message Sequence Charts</a>? </p>
  
  <p>If not, how would you go about it?</p>
  
  <p><img src="https://i.stack.imgur.com/TgLYP.png" alt="A Message Sequence Chart, yesterday"></p>
  
  <hr>
  
  <p>Update: btw, I should have made it clear am not trying to create an app to allow users to manually draw MSCs, otherwise I would simply use TMS Diagram Studio (see my "answer" below).</p>
  
  <p>What I want to do is to auto-generate MSCs from trace logs. So, I will write some code to parse the log file and then would like a components to allow me to define columns and then add arrows to show the message sequence of the trace log.</p>