PodBrowser is a documentation browser for Perl. You can view the documentation for Perl's builtin functions, its "perldoc" pages, pragmatic modules and the default and user-installed modules.

MP3FS is a read-only FUSE filesystem which transcodes audio formats (currently FLAC) to MP3 on the fly when opened and read.

Netplan reads YAML network configuration files which are written by administrators, installers, cloud image instantiations, or other OS deployments. During early boot it then generates backend specific configuration files in /run to hand off control of devices to a particular networking daemon.

Filesystem in Userspace (FUSE) is a simple interface for userspace programs to export a virtual filesystem to the Linux kernel. It also aims to provide a secure method for non privileged users to create and mount their own filesystem implementations.

PowerDNS is a versatile nameserver which supports a large number of different backends ranging from simple zonefiles to relational databases and load balancing/failover algorithms. PowerDNS tries to emphasize speed and security.