Several R packages providing (algorithms to compute) special mathematical functions, typically all related to computing probability distribution functions, often "DPQ" (Density (pdf), Probability (cdf), and Quantiles (inverse cdf)).

Initiated and currently solely maintained by
Martin Maechler,
ETH Zurich,
and member of the R Core team since primordial times.

Traditionally, I have worked a lot in making the DPQ-functions in (base)
R more accurate in border cases, notably implementing
the `log=TRUE/FALSE` and `lower.tail = T|F` possibilities.

### R Packages part of the 'specfun' project on R-forge:

- Bessel:
- DPQ:
- DPQmpfr:
- dcdflib:

see the **R Packages** menu item on the project summary page,
currently available here.
The **project summary page** you can find **here**.