OVERVIEW: Objective Caml is an implementation of the ML language, based on the Caml Light dialect extended with a complete class-based object system and a powerful module system in the style of Standard ML. Objective Caml comprises two compilers. One generates bytecode which is then interpreted by a C program. This compiler runs quickly, generates compact code with moderate memory requirements, and is portable to essentially any 32 or 64 bit Unix platform. Performance of generated programs is quite good for a bytecoded implementation: almost twice as fast as Caml Light 0.7. This compiler can be used either as a standalone, batch-oriented compiler that produces standalone programs, or as an interactive, toplevel-based system. The other compiler generates high-performance native code for a number of processors. Compilation takes longer and generates bigger code, but the generated programs deliver excellent performance (better than Standard ML of New Jersey 1.09 on our tests), while retaining the moderate memory requirements of the bytecode compiler. The native-code compiler currently runs on the following platforms: Alpha processors: all Digital Alpha machines under Digital Unix or Linux Sparc processors: Sun Sparc under SunOS 4.1, Solaris 2, NetBSD, Linux Intel Pentium processors: PCs under Linux, NextStep, FreeBSD, Solaris 2 Mips processors: SGI workstations and mainframes under IRIX 6 HP PA-RISC processors: HP 9000/700 under HPUX 9 and NextStep PowerPC processors: IBM RS6000 and PowerPC workstations under AIX 3.2, PowerMacintosh under MkLinux, LinuxPPC, Rhapsody Motorola 680x0 processors: Sun 3 under SunOS Strong ARM processors: Corel Netwinder under Linux DOCUMENTATION: The Objective Caml manual is distributed in HTML, PDF, Postscript, and DVI. It can be obtained by anonymous FTP from ftp.inria.fr as described below. It is also available on the World Wide Web, at http://caml.inria.fr/ocaml/ AVAILABILITY: The complete Objective Caml distribution resides on ftp.inria.fr, and can be accessed by anonymous FTP: host: ftp.inria.fr (192.93.2.54) directory: lang/caml-light or through a Web browser at ftp://ftp.inria.fr/lang/caml-light/