pf rules work a little backwards compared to iptables. A packet traverses the entire ruleset and the last rule to match wins. You can short-circuit this with a "quick" directive. It takes a bit of getting used to coming from iptables.

The logging on pf doesn't integrate with syslog automatically like iptables does. You're expected to set up a logging system for your particular use case. There are several ways to do it, and for production you'd be doing it regardless, but for honelab setups it's an extra thing you need to worry about.

I prefer pf, but I don't recommend it to people new to firewalls.

For most C and C++ software, you use the system packaging which uses libraries that (usually) have stable ABIs. If your program uses one of those problematic libraries, you might need to recompile your program when you update the library, but most of the time there's no problem.

For your company's custom mission critical application where you need total control of the dependencies, then yes you need to manage it yourself.

But I'm willing to bet that he'd have pushed for GPL if he wasn't trying to topple MP3.

The Ford 351 is a bit special because there were two different engines made by Ford in the same time period with the same displacement, so they tacked on the city they were manufactured in (Windsor or Cleveland).

Windows owns the industrial space for historical reasons, mostly to do with OPC being Windows-only and software for doing maintenance on field devices originally running on DOS. It quickly became a chicken-and-egg situation - everyone wrote their software for Windows because everyone else wrote their software for Windows. SCO owned a decent chunk of the field before that, but we know how that worked out.

We're seeing some change now that OPC is being phased out. Ignition now has feature parity between Linux and Windows (barring OPC, of course). Windows won't go away any time soon (if ever), but you can now have a fully functioning SCADA system with no Windows at all.

The three companies you list are horrible examples. IBM is kind of a UNIX vendor, sort of, but not like Sun or DEC. They sell solutions, and the solutions that use AIX don't overlap with what Linux was capable of in 1998. I'd argue that, given their complete disregard for Tru-64 and pretty much all things DEC, Compaq was never a UNIX vendor - they just inherited a bunch of legacy systems they needed to support. They certainly didn't push for new Tru-64 based systems. Oracle wasn't a UNIX vendor at all and wouldn't become one for quite some time.

BSD sockets are also a bad example. They were the reference implementation, paid for by DARPA. The entire purpose of BSD sockets was to be copied into other operating systems. You'll notice that Linux copied them as well.

IBM and Compaq invested in Linux because they wanted something that ran on their lower-end server hardware and could handle web traffic. Oracle invested in Linux because they wanted to be the backend to all these new websites that were cropping up.

IBM, Oracle, and Compaq didn't give a rat's ass about the operating system code - they wanted the platform. If Linux had never happened and FreeBSD became the new hot thing all the online hackers were talking about, the result would have been exactly the same. They'd have poured money into the projects rather than trying to make their own thing because that's the financially sensible thing to do. The UNIX wars were over, and proprietary software lost.

Meanwhile, the last major UNIX vendor - Sun Microsystems - was giving away its own source code under the CDDL. FreeBSD ended up adopting a lot of it. That's the complete opposite effect from what you're talking about.

Sun got involved in the GNOME project and even deprecated their own CDE desktop in favor of it. Was it because it was GPL? No. It was because they saw that all the new desktop software was coming out of the Linux community, who didn't have access to CDE. Even if GNOME had been BSD licensed they would still have switched to it, because they were still trying to keep the workstation market alive at that point and CDE was quickly becoming irrelevant.

As far as I can see, the only companies interested in taking operating system code were the network appliance vendors and Apple. It only worked for them because they didn't care about compatibility.

Linux came around at the right time when the Internet was going public and regular people had access to hardware that could run a decent UNIX. People latched onto it because it was free and an interesting project. The free BSDs were just late enough to the party that they missed out on the momentum.

All the proprietary UNIX vendors (other than SCO) relied on expensive proprietary hardware sales. Intel ate their lunch while they were too busy stabbing each other in the back to notice. Linux killed SCO because SCO was, quite frankly, overpriced crap.

None of this had anything to do with the license, other that the fact you could use it for free. It was all about hardware availability, the rise of the Internet, the wave of new IT people who had experienced Linux at home, and the fact that Linux on Intel was good enough to replace those pricy proprietary machines.

Now, you wanna talk Apple, there's where your code "theft" kicks in. But that's a whole different thing.

From what I've seen, the BSD community swaps code around on a regular basis. But they pick and choose what code to use based on their own goals. It seems to work pretty well.

My main reason for using NetBSD for this is to have easy access to the man pages. Like the other BSDs, the man pages are exceptionally well-written and are a tremendous resource for doing POSIX programming. Plus I find myself digging through the code when I'm interested in how something is implemented. Having a local repository of good C code with a liberal license is worth having the extra OS to manage.

NetBSD is great for retrocomputing, since it's a modern OS that can run on very limited hardware. It's also a very nice traditional UNIX. It's well documented, has a nice codebase, and is a pleasure to use. But for saving e-waste, Linux has it beat.