A wallflower: That's how I used to describe Thinstall when discussing the movers and shakers of the application virtualization party scene. With its chief competitors already paired off and dancing up a storm, Thinstall looked more and more like the lonesome loser, dateless and stag at the junior prom.

Fortunately, this awkward teenager eventually grew up. With its soulmate VMware by its side for support, the recently renamed ThinApp is now taking its first tentative steps into adulthood. And from where I'm standing, the suddenly more mature and polished application virtualization product looks to be heading in the right direction.

For starters, the core development team -- wisely kept intact during the transition -- is finally starting to tackle some of the lingering design issues that hampered Thinstall's scalability. For example, the product's new AppSync feature addresses a major shortcoming of previous versions: the inability to manage virtualized application packages outside of the normal enterprise IT infrastructure. By embedding a simple HTTP-based synchronization engine into each package, ThinApp makes it possible to slipstream updates for even the most far-flung virtualized applications, using nothing more than a lowly Web server as the distribution and control point.

Sync and link

As approaches go, it's almost fiendishly simple, yet still manages to address an issue that Microsoft and Symantec have been struggling with for years: how to effectively maintain virtualized applications that are distributed over the Web. With ThinApp, this is trivial. Flip a few bits within the package.INI file and you've got an application that phones home on a regular schedule, updates itself if it finds a newer version available at the designated URL, and knows to shut itself down if it loses contact for too long. By leveraging Web protocols in this way, ThinApp bypasses the need for a complex management server infrastructure, making it possible to exploit the robust, proven technology of the venerable HTTP server to scale up to levels only dreamed of by its competitors.

Another ThinApp innovation -- AppLink -- allows an organization to distribute certain shareable software components as discrete ThinApp packages that can then be pulled in by other ThinApp packages at runtime. VMware uses the example of the .Net framework to demonstrate AppLink, but I can think of all sorts of ways that IT shops might leverage such a feature, from distributing and maintaining Java Runtime Environments (JRE) to packaging platform-specific ODBC drivers. In fact, any kind of software prerequisite is a candidate for discrete packaging through AppLink.

Other welcome new features include the ability to package applications as either executable (.EXE) or Microsoft Installer (.MSI) objects; system snapshots for capturing application installations that require a reboot; and support for USB keys as a package distribution medium.