JSS Article: Article about the metafor package published in the Journal of Statistical Software.
Other Free and/or Open-Source Software
Center for Evidence-Based Medicine @ Brown: The CEBM at Brown University has supported the development of the metafor package in various ways (also by providing some financial support). In addition, the center has developed Open Meta-Analyst and OpenMEE, two open-source software packages for conducting meta-analyses that make use of the metafor package as part of the backend.
Meta-Analysis Task View @ CRAN: The meta-analysis task view on CRAN (curated and maintained by Michael Dewey) provides a nice overview of the various R packages related to meta-analysis.
Review Manager: The Review Manager (RevMan) is the software tool used for preparing and maintaining Cochrane Reviews.
MAVIS: MAVIS is a Shiny based web application for meta-analysis that makes use of metafor and a couple other meta-analysis packages under the hood.
Commercial Stand-Alone Packages
Comprehensive Meta-Analysis: User-friendly commercial software package developed by Michael Borenstein (and others) for conducting meta-analyses.
MetaWin: Another commercial software package for meta-analysis (but hasn't been updated since 2007 and not sure if this package is still available).
EPPI-Reviewer: Web-bsaed software developed by the EPPI-Centre for all types of literature reviews, including systematic reviews, meta-analyses, narrative reviews, and meta-ethnographies. Makes use of metafor on the backend for the analytic functions. Free access available for Cochrane authors.
Add-Ins for Commercial Packages
David Wilson: In connection with the book Practical Meta-analysis, David Wilson has written a number of macros for conducting meta-analyses in SPSS, Stata, and SAS. The macros are available for free.
MIX: MIX 2.0 is an add-in for performing meta-analyses in Excel. An evaluation version is available for free (but only works with the built-in datasets).