The Integrated Development Environment (IDE) is used for writing the code and uploading it to Waspmote and Plug & Sense!. It is also used to monitor serial output and for debugging. This IDE contains the Waspmote API (the API is the set of all libraries Waspmote needs for compiling programs). New API versions are released instantly by Libelium whenever improvements are made or bugs fixed.
All information about the IDE installation and operation can be found in the IDE User Guide.
All the documentation is located in the Development section in the Libelium website.