Rattle – the R Analytical Tool To Learn Easily – is a popular GUI for data mining using R. It presents statistical and visual summaries of data, transforms data that can be readily modelled, builds both unsupervised and supervised models from the data, presents the performance of models graphically, and scores new datasets. All of the underlying R code is presented as a script for learning R and for running independent of Rattle.
Rattle is widely used by independent consultants and for teaching data science at many universities.
The package is hosted on Bitbucket where anyone is welcome to clone and provide push requests for updates.
There is an active community of crowd funded developers (more welcome) over on Connect-R where features can be requested.