Some grep alternatives try to be fast by not searching everywhere. sift was developed with performance in mind and just is fast.
Take a look at the benchmarks for details.
sift comes as a single executable with no dependencies and is available for all major platforms (Linux, Windows, OS X, BSD)
Need to use sift on a remote server? Just copy it over and it will work - no problems due to missing packages.
Doing code audits? Need to extract data from complex formats? sift will make this much easier.
You may specify various conditions and only get matches...