The package provides the \collect@body command (as in amsmath), as well as a \long version \Collect@Body, for collecting the body text of an environment.

These commands are used to define a new author interface to creating new environments. For example:
\NewEnviron{test}
wraps the entire environment body in square brackets, doing the right thing in ignoring leading and trailing spaces.

The author is Will Robertson. The package is Copyright © 2007, 2013 Will Robertson.