MCS is a extension of Pike language. MCS allow you to write "Manageable" code, which means you can place all the codes about a special FEATURE in one place, so you can remove it whenever you don't need this FEATURE.
A FEATURE is made up with some MIXINs and a DAEMON. To use a FEATURE named MY_FEATURE just place a line IMPORT(F_MY_FEATURE) in your main source file. remove this line to disable MY_FEATURE.
Spear is a extension of Pike language . Spear allow you put inline C/Java code in Pike, and exchange data cross languages. In additional, Spear can transfer thread to system process, running on multiprocessor, or even cross machines over SSH.