Indeed. Although in principle and only fpc.dll to fpc execuatable (or delphi dll and delphi executable) can work both ways with strings if a shared memory manager is installed.(e.g. sharemem.dll for Delphi)
But generally do not use Pascal strings, with shared libraries use PChar string types. That will also work with other languages.
The exception is COM dll's and their type libraries, together with the use of BWSTR/WideString types: these will work since those are not reference counted by FPC but by a COM marshaller but that depends on platform (usually windows only)