software
Programs I wrote, mostly because I needed them myself. All of them are free.
pcapmirror
Captures network traffic on one machine and mirrors it to another, straight into a running Wireshark or to any collector that speaks TZSP or ERSPAN. It's like a remote span port in one command. You can use BPF capture filters as in tcpdump, it works over IPv4 and IPv6, and it's a single small C program that only needs libpcap, so it also runs on routers and Raspberry Pis. Packages for Debian, Ubuntu, Raspberry Pi OS, Rocky Linux and Homebrew are available.
fsTrack
A battery-friendly GPS tracker for Android that sends every point to your own Traccar server. One button starts and stops a recording. Points recorded offline are queued and sent later. Every track is also saved as a GPX file and can optionally be uploaded to OpenStreetMap. A version without Google libraries is available for phones without Play services. No ads, no analytics, no account.
fsPhone
A SIP phone for Android and the Linux desktop for your own SIP accounts from your PBX, your provider or your company. It handles multiple accounts, hold, call waiting, blind and attended transfer, three-way conferences and fax. Audio uses Opus, G.722 or G.711 with SRTP and TLS, and there's a live SIP debug view for when things go wrong. Both versions use the same settings file. No ads, no tracking.
fsOTDR
Software for the cheap USB OTDR modules built around the WCH CH347 bridge, as a replacement for the vendor app. It measures fibers at 1310 and 1550 nm, shows the trace live while averaging and finds splices, connectors and breaks with their loss and reflectance. Results are saved as SOR files and PDF reports. On modules that have them, it also drives the optical power meter, the light source and the visual fault locator. It works offline on Android phones (USB OTG) and on the Linux desktop. No cloud, no account, no tracking.
unborg / borg
A funny nonsense expander and de-expander that came to life one night in the mid 90s. It was written in Turbo Pascal for DOS and later ported to C.