CrystalLabs — Davor Ocelic's Blog

Tech blog about Unix, GNU/Linux, software development, systems administration, cloud, open source, privacy, and ethics.

Unix and GNU/Linux

Origins and history of Unix. CTSS, BTS, Multics, ITS, Unix, C, BSD, Unix wars, Motif, CDE, GNU, Linux. AT&T, Bell Labs, CSRG, UCB, Sun Microsystems, Novell.

Original Unix, BSD, GNU, and Linux books, papers, videos, and similar materials.

GNU/Linux and Debian GNU documentation. Where is it, how to access it. Man, info, tldr, /usr/share/doc/, TAB, IRC, RFCs, HOWTOs, FAQs, kernel docs. Quiz.


VMs, containers, Docker. Dockerfile, images, containers. Docker and docker-compose. Description and use.

OpenStreetMap (OSM)

Computer cartography. OpenStreetMap (OSM), Mapnik, Tirex. WMS, TMS, WMTS, KML, Slippy. Leaflet, OpenLayers, QGIS, Marble. iD, JOSM, Go Map!!, OsmAnd. GPS, GPX.

Computer cartography. OpenStreetMap (OSM), Leaflet, Slippy. Custom map viewer.

Computer cartography. OpenStreetMap (OSM), MapProxy. WMS, WMTS, Slippy, TMS, KML. Custom tile proxy and cache.


Physical one-way data link. 100Mbps ethernet + UDP/IP. File transfer with ncat or socat and tar.

Three-point VPN Gateway. WireGuard, IPTables/NFTables, DNS, dnsmasq. VPN server and Internet gateway on different machines.

Git (Version Control System)

Introduction to file versioning. History of version control tools SCCS, RCS, CVS, Subversion, BitKeeper, and Git. Funny story.

Git. Multiple repository origins. Projects mirrored at different hosting platforms.


Your own blog like Hugo framework, minima-crystallabs theme. Clone and run. Quick success.

ZeroMQ async messaging. Can run brokerless. Runs on top of ITC, IPC, PGM, TCP, TIPC, UDP, or VMCI. BSD sockets-like API. REQ-REP, PUB-SUB, and PUSH-PULL pattern.

SGI IRIX 6.5 Tips
Oct 10, 2005

SGI IRIX 6.5. Misc user tips.

Lt1. Linux, GNU, diskless, single floppy, 1.44MB, 2MB flash RAM, ramdisk, rescue disk.