It is typically run via a command prompt ( cmd ) or a batch file, often taking an XML file as input and producing a BGL file as output. A basic command looks like: bglcomp.exe scenery.xml [2].
Requires the Microsoft XML Core Services (MSXML) 6.0 to function properly [1]. Bglcomp Exe Fsx
It converts human-readable .xml files, which define object placements, textures, and airport layouts, into binary .bgl files [2]. It is typically run via a command prompt
If you are having trouble running Bglcomp, I can help if you tell me: which define object placements