TSO doesn't have XEDIT. That's only in the VM/CMS world. In the Unix and Windows worlds THE, [link|http://hessling-editor.sourceforge.net/|The Hessling Editor], emulates it pretty closely ("closeness" is configurable :-) In TSO, you have ISPF. It works from a similar paradigm, but lacks many of the the more programmable features. For instance, it's possible to use XEDIT as your display manager. ISPF is limited to editing files. :-)

Regarding REXX, I recommend checking out [link|http://www2.hursley.ibm.com/rexx/|IBM's Hursley site]. Lots of pointers to good information there. If you can find a used copy of [link|http://www.amazon.com/exec/obidos/tg/detail/-/0137806515/qid=1073026008/sr=1-1/ref=sr_1_1/002-1715200-4704868?v=glance&s=books|The REXX Language] pick it up. Amazon wants far too much for a new one. [link|http://www.amazon.com/exec/obidos/tg/detail/-/0070236828/qid%3D1073025787/002-1715200-4704868|The REXX Handbook] is well worth getting. It covers REXX in great breadth and detail. There are a couple of chapters dealing with TSO/MVS issues.

ps. the name of one of the authors of chapter 20 should look familiar. ;-)