hash-2.0.0 has been released please read about it here: Earlier today, hash-1.99.x was released to CRAN. This is a stable release and adds some more functions to an already full-featured hash implementation. This version fixes some bugs, adds some features, improves performance and stability. You can read about the hash package in

Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).