Reproducible research is important for science. In an ideal world, every research publication would have accompanying data and code that could be used to re-do the analyses in the paper (including the figures and tables).
However, in practice, not many papers do have accompanying data and code. Even if a paper does have data and code online (as I do for each of my papers), it may be difficult to re-do the analyses, because the versions of the software used may have changed.
In R this is especially problematic, since the main package repository CRAN only officially supports installation of the most recent version of each package. I developed the requireGitHub R package to partially solve this problem. It facilitates use of any version of any R package which is on GitHub.
Today I read an article that goes one step further, and is really important work towards truly reproducible research using R. In Enhancing Reproducibility and Collaboration via Management of R Package Cohorts, Becker et al propose a reproducible research system for R based on “manifests,” which generalize package repositories. In their results section, they use their switchr package to reproduce a result from the DESeq paper, even though the versions of R and all of the packages they used have changed!