The homepage of GPGtools, a port of GnuPG and an associated toolkit to MacOSX. Includes everything you'll need to seamlessly integrate GPG into your desktop experience, from the GPG executable itself to plugins for the Finder, Mail.app, and Mozilla Thunderbird.
json is a command line utility for working with JSON-formatted data on the command line. At its most basic it'll take JSON data, reformat it so that it's easier to work with, and display it in the terminal. It can also be used to extract only certain bits of data from a JSON stream, lint and debug JSON, and filter input in various ways.
Requires node.js, though it isn't a web app.
Tunnelblick is an open source OpenVPN client for MacOSX. You can either checkout and compile the source code yourself or you can download the .dmg packages for it. Note that if you're running Mountain Lion you'll have to grab the unstable version.
Multibit is a lightweight Bitcoin client written in Java and known to run on Windows (32-bit and 64-bit), MacOSX, and Linux. Source code is on Github, installers available. Lightweight - does not locally store the Bitcoin blockchain.
An /etc/hosts file that cleans up a significant amount of internet garbage. linux unix osx indow
Homebrew for OSX doesn't remove dependencies. In these comments is a bit of hackery to make it happen. In a nutshell, brew uninstall foopkg; brew rm $(join <(brew leaves) <(brew deps FORMULA))
A utility that lets you edit disks and recover data, including entire partitions. Supports multiple operating systems.
A Python module which implements interfaces to the native text-to-speech API for whatever platform you're running it on, be it Windows, MacOSX, or Espeak on Linux.
SoloWizard is an interactive website which lets you check off the things you do and don't want on a new MacOSX machine, and it'll generate a shell script (which you can and should inspect for veracity) that will install Chef locally, pull down the appropriate cookbooks, and set up the machine. Helps automate workstation construction, minimizes craft error in some important ways. Be sure that the cookbooks it uses are compatible with your release of OSX, though.