Tree @1.0 (Download .tar.gz)

`tree`

This is Cat's Eye Technologies' tree, a simple command-line tool that displays an indented directory tree. It:

is written in Python (tested with 2.7.6)
is small and has no dependencies besides Python
is in the public domain (see UNLICENSE)
is really quite crude
displays a summary of the directory structure by default (because to me, that's the point of this sort of tool: give me a conceptual overview of the directory structure at this point in the filesystem, so I can orient myself)
supports one option, --full, which lists all files in each directory instead of giving you the summary
always outputs a / after each directory name
doesn't have any ASCII art (yet; it might someday as the lines do make it a bit easier to "read" the tree)
has no build/install system; either copy it to somewhere on your search path, or alter your search path to include the script directory in this repo, or use some system that solves this problem, like toolshelf.

tree [-f|--full] [DIRECTORY]

The Tree Command for Linux — GPL'ed and feature-bloated and has no automated build system (you're supposed to edit the Makefile by hand.)
pyr/tree — fine if you're running OpenBSD I suppose, but I gave up on trying to port it to NetBSD and Linux and wrote this instead.