- Write R scripts or projects using CRAN package versions from a specific point in time;
- Share R scripts with others that will automatically install the appropriate package versions (no need to manually install CRAN packages);
- Write R scripts that use older versions of packages, or packages that are no longer available on CRAN;
- Install packages (or package versions) visible only to a specific project, without affecting other R projects or R users on the same system;
- Manage multiple projects that use different package versions;
- Write and share code R whose results can be reproduced, even if new (and possibly incompatible) package versions are released later.
The biggest change with this new version of checkpoint is that it checks whether package versions have already been installed for your project: running a checkpoint'ed script for the second time has virtually no overhead now. There's also better feedback during the scanning phase while it determines which (if any) packages need to be installed. You can also now control where packages are installed on your system (the default is a .checkpoint folder in your home directory), and check the specific version of R in use when checkpoint is called.
If you're interested in learning more about how checkpoint works, you can read the new vignette Using checkpoint for reproducible research, or follow its development at the checkpoint Github page. You can install checkpoint from CRAN now by running install.packages("checkpoint") at the R command line.