It's a very small web application that generates graphs as PNG images. You might consider it a bare-bones graph pastebin application.

You enter a graph or digraph definition. You click the button. You get a link to the generated PNG file.

You can generate PNG files with short names (incrementing series, so that makes the URLs easy to guess) or long names (40 characters hex string; need to know graph definition to guess).

• GraphViz installed in /usr/bin. You can edit gen.php if you have a different path.
• PHP 5 or newer.
• MySQL 3 or newer (tested with 5.x).
• The .htaccess file included with it needs Apache with mod_rewrite enabled (and .htaccess files allowed, obviously). You can probably create an alternative solution for most other web servers. Basically, any request to 123abcABC_-.png needs to be rewritten into get.php?id=13abcABC_-.

If you configure your webserver to require HTTP authentication on gen.php, graphs can only be created by known users. Instagraph will log the name of the user for each created graph in the database, though the value won't be displayed anywhere. (Instagraph also logs the time at which each graph was generated; this value isn't displayed, either...)

Anything interesting to say? Tell me at [email protected].