One open source effort that I consistently find myself surprised that very few people mention more is the Funambol project. Formerly known as Sync4j, Funambol is according to their website:
Funambol is an open source mobile application server that provides push email, address book and calendar (PIM) data synchronization, application provisioning, and device management for wireless devices and PCs, leveraging standard protocols. For users, this means Blackberry-like capabilities on commodity handsets.
Funambol is also a development platform for mobile applications. It provides client and server side Java APIs, and facilitates the development, deployment and management of any mobile project. Funambol is the de facto standard implementation of the Open Mobile Alliance Data Synchronization and Device Management protocols (OMA DS and DM, formerly known as SyncML).
For the past two years plus, as open source has experienced growth on the server side, I have continually to looked for Funambol to emerge as a strong force within the mobile synchronization/provisioning. The value of investing in open source on the server side in terms of enterprise application infrastructure and middleware (application servers, development frameworks, underlying operating systems, etc.) are quite evident (lower costs, more flexibility, community support) and in my opinion the same thing holds for the mobile applications. With OMA DS and DA (buoyed by industry support) providing an open definition of the protocols related to device management and remote synchronization, open source implementations are a good fit.
Funambol basically helps you get data and applications onto mobile devices. With more than 1 billion devices out there and nearly 750 million sold each year, there is a need to enable the ability to tap their growing computing capacity. Despite the fact that most people rely on mobile devices everyday, they often forget how capable they are. They can do a lot of different things to increase productivity and flexibility.
With Funambol, allows you to get data from an array of sources onto any device (mobile phone, PDA, iPod, laptop etc). Applications that operate in sometimes connected environments can be developed. Applications that can reach the data its users need when they need it, without having to tightly couple it to brittle, home-brewed access methods. Funambol enables the development of applications that can synchronize at start-up and can handle dynamic, bi-directional synchronization. While also taking care of remote device management using open standards.
After a $5 million Series A from Walden International and H.I.G. Ventures in August 2005, Funambol is in the process of making the transition from successful open source project to viable open source ecosystem that includes enterprise support, partner & reseller networks, in addition to an open source development community. The key for them is how well they will be able to communicate the value of an open source offerings compared to close sourced options already on the market.