This IBM Redbooks publication provides a step-by-step migration guide from previous releases of WebSphere InterChange Server to Version 4.3 for AIX and Windows. A comprehensive outline of the new features of WebSphere InterChange Server after Release 4.1.1 is provided. Planning requirements and pre-migration tasks are discussed in addition to the detailed technical steps required for a successful migration. WebSphere InterChange Server, a key component of WebSphere Business Integration Server, provides the capability to enable heterogeneous business applications to exchange data. It addresses the need for efficiency and flexibility in automating and synchronizing business activities. WebSphere InterChange Server 4.3 provides an important base level for delivering support to new operating systems, as well as reliability, availability, scalability, performance, and security enhancements, including use of open standards. This book is intended for an audience that is familiar with the WebSphere InterChange Server product and wishes to migrate an existing solution on a previous version of WebSphere InterChange Server to Version 4.3. Information is also included for those less familiar with the product or who are interested in an overview of the key new features of WebSphere InterChange Server 4.3. Please note that the additional material referenced in the text is not available from IBM.