Apple Inc.

Free
Highly simple but functional Twitter Client.
Free
We don't have a description for the Apple Messages app yet.
Free
Charla is an open source Mac OS X application for accessing Yahoo! messenger.
The world’s most advanced mobile operating system keeps getting better.
SCIM (the Secure Cryptographic Instant Messenger) is a unique client/server and P2P Instant Messenger that uses a unique combination...
iMessage lets you send messages to anyone on a Mac, or an iPhone, iPad, or iPod touch running iOS 5.
Free
Haven't you ever wanted to mail yourself a link for later use?
Small utilities to view the content of Outlook .msg files.
Email Encoder encodes your email address so that most of the spam bots that go around websites grabbing email addresses are not spidering your email..
Free
Improves the stability and the compatibility with Gmail.
Free
gMailer is an email client for Google's gMail service.
Email PDF helps send a document with out touching personal mail accounts.
One of the fastest way to send emails. It turns any folder on your desktop into an email-sending-box.
Mail Setup was made for people who don't want to look up the settings for their email service and/or mess with settings in mail.
Free
We don't have a description for the Apple Pro Apps Uncompressed app yet.
Free
Apple's Xgrid tech turns Macs into a low-cost supercomputer, ideal for researchers, collaborators, and developers.
Free
Access info about your uploads from App Store, iTunes Store, and iBooks Store.
RADRentalAnalyzer will analyze a potential rental property in terms of cap rate, cashflow, equity, etc.
Tool to quickly switch between 2D and 3D docks on Mac OS X Leopard.
We don't have a description for the Apple iDVD app yet.