To spur development around Microsoft’s Silverlight technology and the Windows Phone 7 (WP7) smartphone platform, McObject has changed its licensing and distribution for the Perst for .NET object-oriented, open source embedded database system.

For a limited time, Perst is available for use in commercial applications on WP7 for a one-time charge of $395 per developer, with free distribution in an application running on consumer mobile phones. This change eliminates run-time royalties, making it easier to distribute mass-market WP7 smartphone software that embeds Perst.

In addition, McObject has temporarily lowered Perst’s price to $495 for use in a commercial Silverlight application that runs on a PC. The change discounts the previous server licensing fee by 38 percent. The new pricing is aimed at designers of rich Internet applications, such as software-as-a-service (SaaS) providers, who deploy Perst in software that is accessed by client PCs (or other devices) to obtain Silverlight’s out-of-browser experience, with local database storage.

Perst remains an open source database system that can be used freely under the terms of the GNU Public License (GPL). Perst for .NET is available for free download here.

Developers questioning whether WP7 devices’ tight memory, CPU, and storage constraints will permit use of a “real” embedded database can look to Perst’s successful track record on BlackBerry smartphones. In 2006, McObject released Perst Lite, an edition of Perst for the Java ME technology used on BlackBerry. Since then, developers have successfully integrated Perst Lite in commercial and open source software for BlackBerry devices ranging from mobile customer relationship management (CRM) clients to banking, consumer, healthcare, and other vertical market solutions.

Perst and Perst Lite are part of McObject’s family of small footprint, embedded database software products. The eXtremeDB in-memory embedded database, which is written in C and includes C/C++, SQL ODBC, and Java Native APIs, is used widely in devices including MP3 players, WiMAX base stations, digital TVs, telecom/network communications equipment, and military/aerospace technology. Perst is available in Java and .NET editions, including Java ME and .NET Compact Framework.

For more information about developing for Windows Phone 7, see Gaston Hillar's Developing a Silverlight UI for Windows Phone 7 in Dr. Dobb's Mobile Developer.