The program produces graphs showing which entity targets which (button -> light, trigger_once -> func_door, etc.) so you can easily visualize complicated entity logic.
The program can output .SVG - the main vector format. If open in a browser you can do default page text search with CTRL+F. Also you can render the graph as .PNG.
Supports filtering entities by class and name.
Works also on Windows XP (requires .NET 4.0 and C++ 2005 Redistributable)
Check the Readme for details.