command-not-found.com
Search the manual pages for names and descriptions. More information: <https://manned.org/apropos>.
Get or set program I/O scheduling class and priority. Scheduling classes: 1 (realtime), 2 (best-effort), 3 (idle). Priority levels: 0 (the highest) - 7 (the lowest). More information: <https://manned.org/ionice>.
Web-crawling framework. More information: <https://scrapy.org>.
Shows the status of Linux kernel modules. See also modprobe, which loads kernel modules. More information: <https://manned.org/lsmod>.
Manage the "snap" self-contained software packages. Similar to what apt is for .deb. More information: <https://manned.org/snap>.
Fix common problems on an NTFS partition. More information: <https://manned.org/ntfsfix>.
Convert a large-sheeted PDF into multiple A4 pages for printing. More information: <https://pdfposter.readthedocs.io>.
Produce simple man pages from an executable's --help and --version output. More information: <https://www.gnu.org/software/help2man>.