EmTeX for PCs running MS-DOS or OS/2, MiKTeX and XEmTeX for PCs running Windows and OzTeX for the Macintosh, all come with previewers that can be used on those platforms. EmTeX's previewer can also be run under Windows 3.1.
Commercial PC TeX packages (see commercial vendors) have good previewers for PCs running Windows, or for Macintoshes.
For Unix systems, there is one “canonical” viewer,
Xdvik is a version of
xdvi using the
web2c libraries; it is now built from the same distribution
xdvi. The TeX Live distributions for Unix systems
include a version of
Alternatives to previewing include