R project has been participating in Google Summer of Code (GSoC) since 2008. We have numerous packages which have received code contributions from GSoC participants. This year too, R is participating and there is already an impressive list of potential projects listed at [https://github.com/rstats-gsoc/gsoc2018/wiki/table-of-proposed-coding-projects] and the project mentors are seeking students to work on these projects.
The applications are open now and students have time till 27th March 2018 to complete the applications. If you know any full time university students interested in R, this is a great opportunity to contribute some code and earn stipend over summer.