Priasoft has several MSG related products. http://www.priasoft.com
In particular, they have a MSG file parsing library that gives developers access to all the properties of a .msg file, without outlook.
They also have an export library that works with the MSG library for exporting msg files to other formats, like PDF, TIF, and HTML.
For PST files, they have a couple of command line tools that allow extraction of messages to MSG, again without requiring outlook, and it supports both ANSI and UNICODE pst files. There is also the reverse, a MSG to PST utility.
They also have a viewer product that looks very similar to outlook 2003 with regards to the User Interface. The viewer can view, search, print, and export msg files.
Lastly, they just release a free ViewOnly viewer here: http://www.priasoft.com/msgview.exe
the MSG Guru, Eriq VanBibber
ALT160 - Do you see me?