Here's a quick introduction to the structure of the SCons repository.

When you first check out SCons, the main directories you will see are:

The src directory is the one you probably care about. It is organized like this:

• engine: the guts of SCons
  • SCons: the root of the SCons python module hierarchy
    • *.py: the python modules
    • *Tests.py: unit tests, discovered automatically; see TestingMethodology
    • Tool: Tool modules, e.g. cc.py, msvc.py, latex.py...
    • Scanner: Scanner modules for dependency scanning
    • Node: the Node object, the central filesystem abstraction for building the dependency graph
    • Script: Main.py in here has the main loop that parses SCons options and reads the SConstruct; it's what's called from the "scons" script
• script: the "scons" wrapper script

Some key files in src/SCons:

• Environment.py: SCons Environment class: the user way to communicate dependencies and construction information to the SCons engine
• Node/FS.py: File() and Dir() nodes are defined here