DataEngines are a key concept in Plasma. They are objects which serve to deliver some kind of data to one or more Plasma applets or plasmoids. Separating the part of the code that supplies the data from the part which displays the data, means that one DataEngine can be reused by many applets, regardless of which language the DataEngine or applet is written in.
Plasma supports out of the box many different DataEngines, which deliver all kinds of varied information about things like the state of the machine, e.g. CPU usage, memory usage, position of the mouse pointer and Internet access. It is also possible to write new dataEngines. Some of the existing dataEngines include rss-feedreader, microblogging engine and weather service report.
Useful tool for anyone working with dataEngines is