On the subject of Windows enhanced ASCII text editors for manipulating
SGML, take a look at Ultraedit (www.ultraedit.com). I have found this
useful (good macro recording, able to launch other programs (parsers,
etc) and the ability to do search and replace (with regular expressions)
within directories of (unopened) files, and a whole lot more. It is
shareware ($30?) but can be tried for free.
Durham University Library