Roxygen is R's analogue to Doxygen; it aims to preserve Doxygen's
basic components: documentation blocks preceding code objects which
describe the objects with key-value pairs.[1] Roxygen will be written
in R; but performance-critical parts may be rewritten in C.

Roxygen's documentation blocks are described by a formal grammar,[2]
but the apposite code objects will be parsed by R's native parse()
facility.

Roxygen will produce an intermediate parse-tree representation to be
parsed by Roclets:[3] drivers that do the actual work of parse-tree ->
Rd, html, LaTeX, UML, etc. translation.

Roxygen will ship with the Documentation-, Namespace-, and
Collate-Roclets with produce, respectively, Rd, package namespace, and
collated package descriptions.[4] If time permits, a Ruml Roclet can
be delivered; along with graphs and diagrams.

A conceivable timeline is as follows: parse R-objects (June 1); parse
Roxygen-tags (July 7); generate intermediate representation (July 20);
translate Rd, namespaces and collations (August 11).[5]

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1. http://roxygen.org/proposal.html#equivalence
2. http://roxygen.org/proposal.html#grammar
3. http://roxygen.org/proposal.html#representation
4. http://roxygen.org/proposal.html#deliverables
5. http://roxygen.org/proposal.html#timeline