Adobe AIR
Adobe AIR is a cross-operating system runtime environment with capabilities which enables web developers to use their existing skills, tools and code to build as well as deploy rich web applications and content to the desktop.

Adobe AIR has a rich combination of features, with support for building applications using HTML, JavaScript, Flex and Flash that can be deployed as a desktop application. Adobe AIR applications also support native desktop integration. AIR includes features like local file IO, clipboard and drag-and-drop support, system notification, and more.

New features provided in the December 2008 release include:

• Encrypted Local SQL Database Support.
• Debugging Support for JavaScript.
• Features of Flash Player 10 comprising Pixel Bender, 3D effects, New Drawing API, Support for secure Dynamic Media Streaming & Dynamic Sound API.
• Updated DRM (Data Resource Management) Engine.
• Updated version of WebKit including “Squirrelfish” a new byte code interpreter. It greatly improved JavaScript performance.
• Support for five additional languages (Swedish, Dutch, Czech, Turkish, and Polish).

Titanium
Titanium is the first open source, multi-platform environment for building rich desktop and mobile applications using a common set of web technologies. Titanium is open source and is licensed under the Apache Public License (version 2).

Developers like Titanium because it uses standard HTML, CSS and JavaScript code to build Rich Desktop Applications. Titanium is currently available in Windows and Mac versions with a Linux version still to come. Titanium is also open API and rich desktop capabilities can be added to applications using JavaScript API.

The salient features of Preview Release 1 (PR1) of Titanium are:

• Support for development on Windows and MAC Platforms
• Desktop Notifications
• Built-in support for Databases
• An Application and System Menu Control
• File system Access
• Command Line Interface for Packaging Applications
• Native Windowing

Comparison
Both Titanium and AIR come with their pros and cons. AIR is more mature, widely accepted, and trusted because of its connection with Adobe.  Titanium is still in evolving and in the testing phase but boasts the advantages of being open source, giving it the advantage that everybody in global community of developers can get benefit from it.

If we look at the environments from a purely technical aspect, Titanium has to mature significantly before reaching the rank of AIR. If compared to AIR, Titanium lacks several features like Flash Player Capabilities, efficient byte code interpreter and the use of standard SQL APIs. In terms of platforms, both AIR and Titanium work well with Windows.

However, AIR includes Linux in its platform range while Titanium prefers Mac. Though Titanium has promised a Linux-based environment, it is still to come.  Mac applications do exist for AIR but not in a fully stable form yet.


Conclusion.
According to Nolan Wright, CTO at Appcelerator, the company that created Titanium, “Adobe AIR is a great product but we really believe there is room for frankly a need for an Open Source Alternative. Our job is to make Titanium open, easy to use and easy to extend.” It is evident that though Titanium promises the benefits of Open Source, there is a long way to go in order to surpass AIR or become a real rival. As Titanium is still evolving, there is a lot more to come.  Our opinion?  AIR is superior to Titanium.

References.
Rob Christensen (2008). Adobe AIR 1.5 now available for Linux. Retrieved Dec. 29th, 2008 from blogs.adobe.com/air/2008/12/adobe_air_15_now_available_for.html
onair.adobe.com/air/
appcelerator.org
titaniumapp.com
www.adobe.com/devnet/air/