The open source movement was a revival of the old days of SHARE and other
user groups.
Amen, my basic point, although I was also trying to pointing at that these user groups got started because the vendors gave the sources to their products out. We SHARED patches and features. DECUS started out the same way. For instance, many/most PDP-10 OS's used the DEC compilers and often even found a way to run TOPS-10 binaries by emulating the UUOs. The IBM/360 world worked pretty much the same way. My own experience was that the compilers (e.g WATFIV-FTNG-ALGOLW-PL/1) and language interpreters (APL-Snolbol) for the TSS and MTS had been 'ported' from the IBM-supplied OS [my own first job was doing just that].
The same story was true for the PDP-8 with DOS-8/TSS-8 and the like. By the time of the PDP-11, while some of the DEC source code was available (such as the Fortran-IV for RT-11/RSX), since it took at PDP-10/BLISS to support it, DEC had it its protection - so moving it/stealing it - would have been harder. By the time of the VAX, DEC was charging a lot of money of SW and it was actually a revenue stream, so they keep a lot more locked up and had started to do the same with PDP-10 world.
So, the available/unavailable source issue came when things started to get closed up, which really started with the rise of the SW industry and making revenue with the use of your SW. OEMs and IVSs started to be a lot less willing to reveal what they thought was their 'special sauce.' Some/many end-users started to balk. RMS just took it to a new level - just look at how he reacted to Symbolics being closed source :-)
The question that used to come up (and still does not an extent) is how are the engineers and teams of people that developed the SW going to be paid/renumerated for their work? The RMS/GNU answer had been service revenue [and living like a student in a rent-controlled APT in Central Sq]. What has happened for most of the biggest FOSS projects, the salaries are paid for firms like my own that pay developers to work on the SW and most FOSS projects die when the developer/maintainer is unable to continue (if not just gets bored).
In fact, [I can not say I personally know this - but have read internal memos that make the claim], Intel pays for more Linux developers and now LLVM developers than any firm. What's interesting is that Intel does not really directly sell its HW product to end-users. We sell to others than use our chips to make their products. We have finally moved to the support model for the compilers (I've personally been fighting that battle for 15 years).
So back to my basic point ... while giving the behavior a name, the idea of "Open Source" is really not anything new. While it may be new in their lifetime/experience, it is frankly at minimum a sad, if not outright disingenuous, statement for the people to try to imply otherwise because they are unwilling to look back into history and understand, much less accept it as a fact. Trying to rewrite history is just not pretty to witness. And I am pleased to see that a few folks (like Larry) that have lived a little both times have tried to pass the torch with more complete history.
Clem.