Aggregation Operators Package for R
"The process of combining several numerical values into a single representative one is called aggregation, and the numerical function performing this process is called an aggregation function. This simple definition demonstrates the size of the field of application of aggregation: applied mathematics (e.g., probability, statistics, decision theory), computer science (e.g., artificial intelligence, operation research), as well as many applied fields (economics and finance, pattern recognition and image processing, data fusion, multicriteria decision making, automated reasoning, etc.). Although the history of aggregation is probably as old as mathematics (think of the arithmetic mean), its existence has reminded underground till only recent (...). [Grabisch et al, 2009, p. xiii]"
agop is an open source (LGPL 3) package for R, to which anyone can contribute. It started as a fork of the CITAN package.
Package record on CRAN: http://cran.r-project.org/web/packages/agop/