mben

AmigaOS had preemptive multitasking.

Jay Miner was responsible for Atari 8 bit home computers and later for the Amiga.

Check this bootstrap theme: https://github.com/kristopolous/BOOTSTRA.386

Check pf-diverters [1]. We are using them in our openbsd firewalls in order to block unwanted connections.

[1] https://github.com/echothrust/pf-diverters

Yes, iRedMail (http://www.iredmail.org/) on Digital Ocean. The $10/mo VM is enough for a low traffic mail server.

Theo's opinion about BoringSSL and LibreSSL portability: http://article.gmane.org/gmane.os.openbsd.tech/37174

NetBSD has hired a developer to port Linux DRM to NetBSD with support for KMS and GEM: http://mail-index.netbsd.org/tech-x11/2013/02/06/msg001229.h...

PFSense is using an older and patched version of OpenBSD PF and as you said all the configuration is done using the gui. PF configuration in OpenBSD is very simple using the cli and following the official FAQ: http://www.openbsd.org/faq/pf/index.html

Check also the Unix Toolbox: http://cb.vu/unixtoolbox.xhtml I've got a copy of the pdf in my dropbox just in case.