The most important ways to use findlib Findlib and the toploop For a number of platforms, O'Caml can load bytecode-compiled libraries dynamically. For these platforms, findlib is very simple to use as explained in the following. For other platforms, see the paragraph below about "custom toploops". After the toploop has been started, it is possible to load the special findlib support: Findlib takes care to load packages that are required by loaded packages first. For example, "netstring" uses "unix" and "str" internally, but you do not need to load them because findlib does it for you. In this example you can also see that findlib loads netstring_top.cmo containing printers for the toploop.