Filling in a hole in its Google Apps suite, Google has acquired Tonic Systems, which provides a set of tools for the online editing, viewing, and sharing of presentations created with Microsoft PowerPoint. Tonic Systems describes itself as "Java PowerPoint Specialists." Google says it will incorporate Tonic's technology into a new presentation service that will be added this summer to Apps.

Tonic's TonicPoint tools allow you to open a PowerPoint presentation with your web browser, edit it, add new slides to it, extract text and images from it, and save the edited version in various formats. What makes TonicPoint particularly interesting, in the context of Google's ambitions, is that you don't have to have a copy of PowerPoint installed on your PC to open and edit a PowerPoint file with the tools. You only need the file. You can, effectively, work in a Microsoft app without buying the Microsoft app.

As with Google Docs and Google Spreadsheets, Google seems to be designing Google Presentations as a hybrid complement/competitor to Microsoft's Office applications. You first use them as add-on tools for manipulating and sharing Microsoft files online, and then, eventually, you find that you don't need the underlying applications anymore. Google Apps, in other words, is designed not as an Office Killer but rather as a kind of Office Bodysnatcher. Google doesn't want to fight the Microsoft apps head-on. It wants to get inside them, and slowly take them over.

Google has wiped the Tonic Systems' web site clean, but, for the moment, a demo of the service is still running here. (Update: It's gone.) Here are some screen shots: