ECL's manual, which is found here http://ecls.sourceforge.net/new-manual/ is being updated on two fronts. The most important part is to document features that were long present but were not explained in the documentation. This includes for instance character types, support for Unicode or external formats, which were erroneously absent from the manual for several years.
The second set of improvements consists on the documentation of its C/C++ API. The manual now lists the C equivalents of almost all Standard Common Lisp functions and types, and in the following days we will add also the functions and macros which are proper just to the C part, such as conversion from all C types to Lisp and back, memory allocation, etc.