Autoplot is an interactive browser for data on the web. Give Autoplot a URL or local file name and it creates a sensible plot of the data. Autoplot allows you to interactively browse data stored in ascii, .cdf, netcdf, and many other formats.
Completions engine helps form data URLs.
Horizontal slice of data
Servlet mode of operation, unsigned applet available as well
Python scripting, e.g. here we use Apache Math library
PNG Walk Tool allows browsing of precalculated images.