Market rejected them because they cost a bit more or didn't have highest, raw performance. Such short-sightedness means most done exist any more in any turn-key form. Many of the modifications are straight-forward enough that even academics are prototyping them and porting Linux/FreeBSD to them.
Mainstream just refuses to learn or adopt proven methods of the past. They use every justification in the world even when the labor is free (FOSS) with someone only asking to use the minimal of proven techniques. Market rarely buys the stuff outside very limited sales of some robust appliances: see Aesec's GEMSOS stuff, SAGE Guard on XTS-400, Nexor Mail Guard (on XTS-400), Green Hill's INTEGRITY-178B OS w/ virtualization, Mikro-SINA VPN on L4, Secure64's SourceT OS for DNS, Sentinel's HYDRA firewall (uses INTEGRITY), and so on. Social, political, and economic problems rather than technical. I see no end to it outside continued sales and development of niche solutions.
Note: The things I referenced in last paragraph are either still on the market w/ descriptions available via Google or at least have papers in reach. I left out tons of good stuff that's no longer around or just a prototype. Happy Googling and learning. :)
https://www.schneier.com/blog/archives/2014/04/dan_geer_on_h...
Market rejected them because they cost a bit more or didn't have highest, raw performance. Such short-sightedness means most done exist any more in any turn-key form. Many of the modifications are straight-forward enough that even academics are prototyping them and porting Linux/FreeBSD to them.
https://news.ycombinator.com/item?id=10522742
Mainstream just refuses to learn or adopt proven methods of the past. They use every justification in the world even when the labor is free (FOSS) with someone only asking to use the minimal of proven techniques. Market rarely buys the stuff outside very limited sales of some robust appliances: see Aesec's GEMSOS stuff, SAGE Guard on XTS-400, Nexor Mail Guard (on XTS-400), Green Hill's INTEGRITY-178B OS w/ virtualization, Mikro-SINA VPN on L4, Secure64's SourceT OS for DNS, Sentinel's HYDRA firewall (uses INTEGRITY), and so on. Social, political, and economic problems rather than technical. I see no end to it outside continued sales and development of niche solutions.
Note: The things I referenced in last paragraph are either still on the market w/ descriptions available via Google or at least have papers in reach. I left out tons of good stuff that's no longer around or just a prototype. Happy Googling and learning. :)