Abstract
The R package dotCall64 provides an enhanced version of the foreign function interface (FFI) to call compiled C, C++, and Fortran code from the software environment R. It allows users to integrate compiled code without using complex application programming interfaces (APIs), such as the C API of R. Moreover, dotCall64 supports long vectors having more than elements and implements a mechanism to avoid unnecessary copies of R objects. Therefore, dotCall64 facilitates making existing C, C++, and Fortran libraries accessible for R and is particularly useful for applications involving long vectors.