Google recently established a deal to acquire AppJet, the company behind EtherPad, a collaborative Web-based editing tool. Google aims to leverage some of AppJet's technology in its own Wave communication service.

When the acquisition was announced last week, enthusiastic users of the service expressed dismay upon learning that the free version was going to be shut down. In response to the concerns voiced by the EtherPad user community, Google and AppJet revised their transition strategy and decided to leave the service up and running until the source code could be made fully available to the public.

The AppJet framework on which EtherPad is built has some very intriguing characteristics. It is a server-side JavaScript runtime that uses Mozilla's Rhino engine. This means that both the EtherPad backend and the browser-based frontend are built almost entirely with JavaScript. EtherPad uses Comet, a technique for achieving persistent HTTP connections, to deliver efficient real-time collaboration. This is likely the characteristic of the software that is most intriguing to Google.

As we explained in our hands-on look at Wave, Google's service strives to offer seamless concurrent editing by leveraging the principle of Operational Transformation. The implementation of Wave's concurrency framework is remarkably sophisticated and represents one of the most innovative components of Wave technology. Google could potentially be looking to boost the responsiveness of real-time collaboration in Wave by adopting some ideas from EtherPad. Google will also benefit from the expertise of EtherPad's lead developers, former Googlers who are now going to be returning to the nest as part of the Wave team.

The EtherPad service itself, however, appears to be of no interest to the search giant. Google intends to shut it down entirely, but has agreed to leave the lights on until the source code can be made available, at which point users will be able to run their own self-hosted instances of EtherPad at no cost.

"We have begun planning how to open source the code to EtherPad and the underlying AppJet Web Framework," wrote former AppJet CEO Aaron Iba in a blog post. "We hope that by releasing the code to EtherPad we will not only help you transition [users'] existing workflow, but also contribute to the broader advancement of realtime collaboration technology."

Google is serious about making the underlying technology of Wave a de facto standard for the next-generation of interactive Internet communication. The company's acquisition of AppJet and plans to release the source code could help advance that goal.