openCR is a new R package for open-population analyses of spatial or non-spatial capture-recapture data. You can get it from CRAN however you usually install R packages (OS X binaries will be available in a day or two). See
https://www.otago.ac.nz/density/openCR.html for features, examples and limitations. The models extend Schwarz and Arnason (1996) and Borchers and Efford (2008). The parameterization of recruitment is flexible (options include population growth rate and per capita recruitment). Cormack-Jolly-Seber and Pradel models are included. Spatially explicit analyses may assume home-range centers are fixed or allow dispersal between sampling sessions (experimental in 1.1.1). Fitting of non-spatial models is somewhat slower than in MARK and the non-spatial capability of openCR is limited. The next release (1.2) will use multithreaded C++ code, for a considerable improvement in speed.