Construction scripts are just Perl scripts, making them both easy to comprehend and very flexible. Multiple environments are used when different semantics are required for generating products in the build tree. Cons implements automatic dependency analysis and uses this to globally sequence the entire build. Variant builds are easily produced from a single source tree. Intelligent build subsetting is possible, when working on localized changes.
Overrides can be setup to easily override build instructions without modifying any scripts.
MD5 cryptographic signatures are associated with derived files, and are used to accurately determine whether a given file needs to be rebuilt. Complaints, suggestions, kudos, etc.