Boost has lots of things. Why is this one particularly interesting?

The Boost Interval Container Library (ICL) is relatively new; it's new from 1.46.0, which came out on 21st February 2011, hence it's quite likely few people have heard of this before.

Also, the underlying implementation (http://www.boost.org/doc/libs/1_46_1/libs/icl/doc/html/boost...) relies on STL sets and maps, rather than using something more exotic like R-Trees or kd-trees, so this might spark some discussion about alternate implementations and their respective complexities.

I say might because intervals...well, don't really do it for me. Anyone have interesting applications?

If you annotate text, you frequently want to attach information to (word or character position) intervals.

And you do complex queries over these interval annotations, e.g. (for a simple example) "which sentences contain both a date and a room number".

Because of the scale of corpora, people often do the storage and queries over SQL databases rather than in-memory, but the principle is the same.