A GXL - Graph Exchange Language File is a file type used with Graph Exchange software. GXL files are a standardized file format type to allow the exchange of graphs and all associated data between different graphing programs.
The GXL file type is written and saved in XML code, storing nodes, edges and the properties that make up the graph properties, to allow the various programs to access, interpret and read the contents of the files. This file type is also supported in Java, assuming that a Java to GXL file has been installed, allowing for cross compatibility.
GXL file types were first published back in the year 2000. They began with a rewrite of the PROGRES graph system, then combining with the TA language and the GRaX types. Other, original ideas, were then added to handle transformation flow. The GXL type created an easier to use version of all these earlier types and became the popular format. The popularity of this early graph format has declined over the years and has been replaced in popularity, for the most part, by a number of other formatting standards for graphs including GML, GRAPHML and XGMML.