PLanCompS is a 4-year joint research project based at Swansea, Royal Holloway and City, funded by EPSRC, starting in September 2011. It will establish and test the practicality of a component-based framework for the design, specification and implementation of programming languages. The main novelty will be the creation of a substantial collection of highly reusable, validated language components called fundamental constructs or funcons. Crucially, the semantic specification of each funcon will be independent, not needing any reformulation when funcons are combined or new funcons added to the collection. All specifications will be provided online in an open access repository, with browsing and searching supported by a digital library interface.