developing addon for all Lms

Hi All,

This question is not specific to Moodle but is general to all Lms systems.

What methods can we adopt if we want to develop a plugin/ addon that will work with all types of lms systems (php, asp.net or jsp).?

For instance if I want to create an addon that is compatable for all types of lms systems. 

What do I need to consider?

Thanks

Vijay