Rserve
- TCP/IP server for other programs to use R from various languages with no need to initialize R or link to R library. Each connection has unique workspace, working directory. Client implementations for common languages (C/C++, Java). Remote connection, auth
- http://stats.math.uni-augsburg.de/rserve/

R_PHP_Online
- PHP CGI web interface to run R programs online, with graphic output. Runs on Unix, Windows, with Web server. Not a PHP extension. Descriptions, documents, downloads. [Open Source, GPL]
- http://steve-chen.net/R_PHP/

R-php
- Coded in PHP and MySQL, to run requires: PHP, MySQL, Apache, ImageMagick, Netpbm. Downloads.
- http://dssm.unipa.it/R-php/

Rpad
- Interactive, web-based analysis package, webpage and GUI designer. Pages are workbook type sheets in R. Makes data analysis programs that share with others easily, via web browsers. Descriptions, documents, downloads. [Open Source, GPL]
- http://www.rpad.org/Rpad/

Rweb
- Web based interface to R, takes submitted code, runs R on it (batch mode), returns the output (printed or graphical). Set up your own Rweb server by downloading source code and support software. Descriptions, documents, downloads.
- http://www.math.montana.edu/Rweb/

Rho
- Integrated toolkit for web deployment of R analysis. Java server/servlet allows concurrent management of multiple projects, packages, users; keeps user analysis state across a session. Descriptions, documents, downloads.
- http://www.rho-project.org/

CGIwithR
- Package to use R as CGI script language. Uses: online calculators, with R as compute engine; processing web forms generally, with R as alternative to more common script languages, e.g., Perl.
- http://www2.warwick.ac.uk/fac/sci/statistics/staff/academic/firth/software/cgiwithr/