A newer feature of Castanet (as of this writing) is the ability to allow Windows or Solaris native-code libraries (DLLs or .so files) to be installed on the local client system (that is, on the system on which the tuner runs) and used by channels that run on that system. Tuner extensions are not downloaded and installed automatically, as normal channel files are; instead, the tuner extension files must be intentionally downloaded installed by the user for your channel to take advantage of them. In this way, tuner extensions are somewhat analogous to browser plug-ins: they extend the capabilities of channels to include specific functionality.
This appendix gives a quick overview of Tuner extensions; more information will appear on Marimba's Web site at http://www.marimba.com/developer/.