Linux in particular, and FOSS in general, are about 10x more difficu=
lt to=20
use in an embedded system than any of the commercial RTOSs or other=20
commercial products. (I base that multiplier on my experience in these tw=
o=20
specific fields.) For more traditionally configured systems (other than=20
embedded), the multiplier would be a smaller number, but still significan=
tly=20
higher than 1x.
     The higher degree of difficulty comes from the absence of enforceabl=
e=20
support. By "enforceable" I mean that if I buy a commercial product, I ca=
n=20
expect a high level of support and, if it is not provided, the supplier c=
an=20
reasonably expect to be sued into bankrupcy. (In practice, of course, it=20
rarely works out that way but, nonetheless, the threat is there and, as a=
=20
consequence, most sellers of commercial software products do a mediocre t=
o=20
good job of post-sales support.)
     FOSS support, on the other hand, comes by mutual consent. Answers to=
=20
problems can't be ensured by intimidation or litigation. Indeed, commerci=
al=20
users of FOSS have to make special efforts to groom the relationship with=
 the=20
support community. (MontaVista's efforts to build good will with the Linu=
x=20
community would be a prime example.) If a FOSS user pisses-off the=20
maintainers, it is very unlikely they will be able to get help.
     I think that in a few years time we will see that FOSS is used as=20
commonly as closed-source, but that both open and closed source products =
will=20
continue to be viable mechanisms for building systems. The important issu=
es=20
then will be whether or not a company 1) has (or is willing to hire) a Gu=
ru=20
in FOSS and, thereby, have sufficient expertise in-house and require litt=
le=20
external support, or 2) subscribe to a FOSS distribution and support serv=
ice,=20
or 3) purchase a closed-source product and support service.
     In a few years time it will be clear that the key issue is support, =
not=20
whether the source is open or closed.

--=20
Ed Skinner, ed@flat5.net, http://www.flat5.net/