[rektide]

As opposed to Spark, the microcontroller platform. As opposed to Spark, the resilient distributed data system. As opposed to Spark, the open source IM client.

[kitd]

... as opposed to Spark (http://www.sparkjava.com/), the Java web server.

[qrohlf]

...as opposed to Spark[1], the tool by @holman.

[1]http://zachholman.com/spark/

[Zikes]

Yep, should've gone with Zitser or Poppler.

[drv]

You were probably being facetious, but Poppler is already used too (PDF rendering library).

[agret]

Would've made more sense for a POP email library.