What it is
OGDL is a structured textual format that represents information in the form of graphs, where the nodes are strings and the arcs or edges are spaces or indentation.
This site is the home page of OGDL and is devoted to the development of specifications and reference implementations in several languages.
An example of OGDL (more examples)
network eth0 ip 192.168.0.10 mask 255.255.255.0 gw 192.168.0.1 hostname crispin