[rainysunday]

The (deprecated) debug module has some screen shots that show margin markers:

http://foicica.com/wiki/lua-debugger

The styling and symbol choice is configurable.

Not sure how inline diff works though (for deleted lines), do you have an example in another editor?

[pepve]

Here is how Netbeans does it: http://netbeans.org/projects/versioncontrol/pages/Git_ui#Inl...

[rainysunday]

What I see on the screenshots there should be possible in Textadept.