I suppose both of them are somekind of frameworks, with the intention to get or become a xoops standard considering modules?

Are there any differences between them? What are the differences between them?
Would it be pratical, usefull or possible to merge them to create 1 standard framework?

These 2 RM/TDM aren't clear to me.

These are two independently developed module frameworks, but with different level of complexity.

The future goal/desire is to have a one module framework that would significantly improve the easy of creating module for XOOPS.

We had in the past discussions about having a one Module Framework, and I believe that this will be one of the goals for XOOPS 2.6 as it is very important for XOOPS, but I let the Core developers speak to it...