Background and Business Requirement
This solution is a result of parallel development efforts involving ADI and one of its long time customers, targeted at developing an IM application for Windows powered Pocket PC (v 3.0) and Palm OS devices running OS version 3.0. The development work is based upon the IMIP-PLUS open protocol.

IMIP (Instant Messaging Interoperability Protocol) - an open protocol developed by IM-Unified (an interoperability forum in which the client is a founding member together with Yahoo, MSN and Excite@home). IMIP - Plus - an IMIP extension, which supports additional unique features that are proprietary to the client’s IM server platform. Clients, which implement the IMIP protocol, can cater to various IM service providers such as Yahoo, MSN, ICQ, AIM, Odigo etc. IMIP - Plus is an extension to IMIP providing additional functionality like simultaneous connections to multiple IM providers and other specific features like searching user.

Peculiarities / Challenges
The development work was carried out in an environment where the severs were undergoing constant up-gradation in order to support various features and resolve server side issues/bugs. This reflected in heavy change management and had to be handled very closely. The support for various IM services like Yahoo, ICQ, AIM, and MSN was carried out in iterative phases i.e. one IM service at a time, as compared to supporting all services at a stretch. Keeping this in mind the design of the client application was spilt into three subsystems viz. API Library, Bridge and the User Interface. This approach served a two-fold purpose; firstly, any IM service supported on the server side could be easily supported by the client with minimal changes on the User Interface. Secondly, since the development of the client application is across platforms viz. Palm OS and Windows CE, effort minimization could be achieved during the client development. This maximum code reusability resulted in quick development and low maintenance issues.

Achievements
The design goals were achieved very practically, where in the IM services were supported successively, as and when the server supported them. Also, separating the User Interface with well defined exposed bridge interfaces resulted in faster development across platforms. In-spite of the extreme change management involved, the development activity was never affected with all changes recorded, notified and accommodated in the project schedule in a planned and phased manner.