A daemon which implements an API bridge to the Signal network. This is for hooking bots into the Signal messaging network as well as connecting other kinds of software and webhooks in.
A very small, very lightweight service monitoring daemon written in Python. Tries to make you install as little other crap as possible.
A daemon that implements the Signal protocol. You have to interact with it through the UNIX socket it opens. You can either register a brand-new phone number for this daemon or add it to the one you already have.
In the AUR.
Human Interface Device emulator for NFC readers. Reads the chip, outputs the contents as if it were a keyboard. Designed to run as a service in the background (or more accurately, a user daemon - since it requires the current user desktop session to function). The ideal time to start the program is on login. To avoid conflicts, the application will only attempt to load once. You may have problems getting it to work after switching users unless the first user logs out completely.
Requires pcscd, Python v2.7.
One of those nifty system monitoring packages, with all the buzzwords you'd expect. Watches systems as well as applications. Has a dashboard, which I think you can disable. Realtime, too. Supports third party extensions and applications. Tries to use as little RAM as possible, tries to carry out as little storage I/O as possible. Claims to have a web API. Zero dependent packages.
Can notify through multiple means, including IRC, email, Pushover, and custom endpoints.
There is an OpenWRT package called 'netdata' which can be installed normally.
A daemon that logs into an XMPP server. Other processes can connect to a port it opens and send messages through it.
Requires slixmpp.
websocketd is a small command-line tool that will wrap an existing command-line interface program, and allow it to be accessed via a WebSocket.
WebSocket-capable applications can now be built very easily. As long as you can write an executable program that reads STDIN and writes to STDOUT, you can build a WebSocket server. Do it in Python, Ruby, Perl, Bash, .NET, C, Go, PHP, Java, Clojure, Scala, Groovy, Expect, Awk, VBScript, Haskell, Lua, R, whatever! No networking libraries necessary.
Small XMPP client daemon for use in embedded systems (OpenWRT, etc). Depends on libstrophe.
A daemon that adds noise to the Linux kernel's entropy pool to maintain a certain amount of randomness. Every little bit helps.
An SMTP daemon that sits between the network and your actual SMTP server (it was designed with Postfix in mind but it should be possible to drop in front of other servers, like Qmail). It runs all SMTP traffic through an antivirus scanner (ClamAV by default) before passing it along to the rest of the SMTP server. Designed to be simple and lightweight (written in C instead of Perl).
How to set up a Subversion server using the svnserve daemon in four easy steps. For passing through to Redmine, it works.
FOSS software that uses an RTL-SDR radio receiver as a cryptographic entropy generator. Pulls samples of RF noise, processes them, and seeds an RNG with it. Written in C.
An experimental ssh and telnet server daemon written in python, meant for developing things like a BBS, a MUD, or a MOO. Built on top of Miniboa, Blessed, SQLitedict, Paramiko, and web.py. web CURSES enabled. Supports ANSI art.
github repo for a fairly simple daemon that polls the system's sensors. When enough fail it runs a script in response. Can be used as a dead man's switch. FOSS Written in C. If you can write a sensor of some kind that monitors for something and emits a zero if yes or good, or not-zero if no or fail, you can probably use swatd for it.
Tiny web server written in Golang that indexes and serves ZIM files. Lets you put a copy of Wikipedia on a relatively small device and serve it in such a way that just about any device on the Net can browser it. Includes its own indexer for search.