Autoplot is an interactive browser for data on the web developed by ViRBO under the NASA Virtual Observatories for Heliophysics program. Type in a URL or a name of a file on your computer and Autoplot tries to create a sensible plot. It was developed to allow quick and interactive browsing of data and metadata. In the same way that you browse content stored in .html, .jpeg, and .png files on the web, Autoplot allows you to interactively browse data stored in .cdf, .nc, ascii, and many more file formats.
To get started, try using some of the demo bookmarks found under "Bookmarks" in the menu bar.
Plug-in data sources are used to load data into Autoplot, using a URI specification. The URI identifies the plug-in and then the plug-in uses the URI and parameters specified there in to read in the data. For example, the ascii table reader URIs are vap+dat:<file>?<params>, and the params identify how to parse the ascii table with parameter names like skipLines and delim. Many data sources are fairly straight-forward to use, such as the CDF reader where a CDF file is identified along with the physical parameter found within the file. Others, like the ascii table reader, have many parameters and autoplot.org describes them. Some have graphical (GUI) editors that make it easier to compose URIs. In this case, try clicking the folder icon next to the address bar, which will enter the editor.