From: torvalds@klaava.Helsinki.FI (Linus Torvalds)
Subject: Re: Is MINIX much better than LINUX?
Organization: University of Helsinki
Date: Sat, 12 Dec 1992 09:09:26 GMT

In article <1992Dec12.034538.14723@netcom.com> sjs@netcom.com (Stephen Schow) writes:
>I need some reasons for buying minix versus just getting linux for free.
>Anyone got any concrete ones.  I won't really be doing any commercial things.
>I just want to get through my BSCS, where all of our programming has to be 
>on UNIX machines.  

Can't pass on this one... The simple answer is a resounding NO.

There are two circumstances when you may find minix better:

 - studies with the book: minix documentation is better, and if you are
   reading the Tanenbaum book, minix will naturally be closer to what is
   covered in the text. 
 - if linux won't run on your hardware (ie PS/2 or any non-386
   hardware, or <2MB memory).

Linux has all the features that minix has (except minix-specific things
like amoeba support), as well as a lot of features minix doesn't have:

 - a real mm taking advantage of the 386 features.  Virtual memory,
   demand-loading, shared pages, the works.  There seem to be patches
   for some of this to minix as well, but I haven't heard how well they
   work. 
 - multithreading filesystem.  'Nuff said.  Available in a limited form
   for minix as a cludge. 
 - better buffer cache handling. The cache grows/shrinks dynamically
   with memory consumption.
 - virtual filesystem layer: you can have several different fs's active
   at once.  The current standard filesystems are: minix (old 1.5 type),
   extended (255 char filenames, 4GB partitions), msdos, proc (for
   process information), isofs (CDROM filesystem) and NFS client fs.
 - floating point support (ie you can use your coprocessor if you have
   one - the kernel makes sure processes don't mess with each others
   state)
 - coprocessor emulation (so that you can ignore the lack of coprocessor
   if you don't mind the performance hit)
 - netowrking support with tcp/ip and NFS (SLIP is in the works)
 - pretty much 100% POSIX and features from both sysv and bsd worlds:
   porting most stuff is mostly very simple. 
 - X11 and most GNU software, as well as a lot of other free software
   out there.
 - shared libraries, so X11 binaries don't take up all your disk space..
 - Active support (me + probably several thousand activists: c.o.linux
   has been on the top-40 lists of most active newsgroups for the last
   couple of months).

And a lot more...

Linux is lacking in (relative to some other unixes, not minix):

 - No sysv shared memory yet (well, there are patches, but not part of
   the official kernel), and no real mmap(). 
 - Not binary compatible with anything
 - Documentation and "real" support (although the c.o.linux newsgroup is
   pretty good)
 - ...?

Ok, after having beaten my breast about linux, I'd also better mention
that 386bsd is also free, and has about similar features.  Linux is
better in some respects: it seems to work on a wider variety on machines
and is actually stabler on some configurations.  On the other hand,
386bsd has a more mature networking setup, as well as having the
advantage of being "the real McCoy".  Check out both comp.os.linux and
comp.unix.bsd for details. 

Note that both linux and 386bsd are good for people who aren't afraid to
set up the system themselves, and are willing to find documentation from
various sources.  Coherent (USD $99) might be an alternative if you want
good printed manuals and don't care about X11 or features, but just want
a simple working unix that has support and is easy to install.  And
although minix doesn't do as much as linux or 386bsd, and doesn't have
the support of Coherent, it's still a real contender in academic courses
etc. 

		Linus
Newsgroups: comp.os.minix