freebsd-ports/devel/cons/pkg-descr

This is a Perl-based make replacement, but does not provide make
compatibility. It has a number of powerful capabilities not found
in other software construction systems, including make.

The official cons web site is http://www.dsmit.com/cons/

Cons is a system for constructing, primarily, software, but is
quite different from previous software construction systems. Cons
was designed from the ground up to deal easily with the construction
of software spread over multiple source directories. Cons makes it
easy to create build scripts that are simple, understandable and
maintainable. Cons ensures that complex software is easily and
accurately reproducible.

`Cons' uses a number of techniques to accomplish all of this.
Construction scripts are just Perl scripts, making them both easy
to comprehend and very flexible. Global scoping of variables is
replaced with an import/export mechanism for sharing information
between scripts, significantly improving the readability and
maintainability of each script. `Construction environments' are
introduced: these are Perl objects that capture the information
required for controlling the build process. 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.

While offering all of the above, and more, Cons remains simple and
easy to use. This will, hopefully, become clear as you read the
remainder of the man page.