Adobe Systems will release a beta of its Apollo runtime software Monday along with a beta of the next version of the company's Flex development environment.

Along with this latest release, Adobe has officially named Apollo "Adobe AIR".

Public betas and software development kits (SDKs) for both AIR and Flex 3 will be available Monday, marking the first time Adobe is simultaneously releasing its programming model and runtime for building rich Internet applications (RIAs) that can be run both on the Web and locally on the desktop, said Michele Turner, vice president of product management and developer relations at Adobe.

Together, Flex and AIR are designed to bridge the gap between developers who write code and designers who use tools such as Adobe Dreamweaver and Flash to build Internet applications that have rich multimedia capabilities. Microsoft is encroaching on the space Adobe currently reigns, however. The company has integrated a version of its .NET runtime into its new Silverlight Web technology which is aimed squarely at Adobe Flash. Silverlight can run video and multimedia applications cross-platform within different browsers.

Both AIR and Flex 3 betas can be downloaded from Adobe Web sites.

Adobe AIR (which stands for "Adobe Integrated Runtime") lets developers take applications built not only in Flash, but also in HTML, AJAX, and other Web-development languages and create them to run locally on a user's desktop. Flex is the development environment that can be used to build applications for AIR.

AIR works as a wrapper, which makes it easy to take code from an existing Web application, wrap it in the runtime, and transfer it to the desktop. Developers can use Flex Builder to transfer Web applications into the AIR runtime, which must be installed on the desktop or embedded directly in the application to enable it to run locally, similar to how the Flash player runs Flash applications in the browser.

New features for AIR that can be found in the beta are enhanced support for HTML, Ajax and Javascript, as well as the ability to integrate the PDF (portable document format) into AIR applications. The beta also includes tighter integration with Adobe's Dreamweaver Web design tool so developers can easily repurpose Dreamweaver applications to run on the desktop using AIR.

Adobe also has added new features to Flex 3's beta, including tighter integration with Adobe's Creative Suite 3 package of Web, multimedia and image creation and design tools. The test version of the Flex 3 also includes a new tool that analyzes the performance of an application while it's being built to let a developer know where it might be running slowly and how it can be optimized to run more efficiently and faster.

Additionally, Adobe has reduced the size of files created with Flex 3 so any application built using the tool will inherently run faster than applications built using Flex 2, Turner said.