Debian on old or slow computer

Consider using LTS or OldStable instead of Stable. Some packages won't be supported in LTS. Links: LTS and CategoryLts.

Replace websites with special software

Use youtube-dl -f fmt (e.g. 36) to download videos from Youtube and other websites and play it with mplayer or vlc. The old version of the english Wikipedia article about YT has a list of YT formats (itags). youtube-dl is in the Backports. Another way to use youtube-dl is to download it to ~/bin and use youtube-dl -U to update it. See JensKorte/youtube-dl. If you get "WARNING: Your copy of avconv is outdated, update avconv to version 10-0 or newer if you encounter any errors." use the libav-tools from backports (as of writing: 6:10.1-1~bpo70+1). That version lacks ffplay which is used by winff to play files.

If your computer is too slow for iceweasel showing OpenStreetMap, try foxtrotgps.

xbmc or xbmc-standalone (xbmc with X but without a window manager) with radio, youtube or Mediathek plugin may or may not be useful for old computers (xbmc requires 24bit colors).

Software

In the Debian repositories

dvtm dwm epdfview gscan2pdf iceweasel with plugins irssi lftp mosh (ssh for slow or unstable connections) nmon pydf qalc rtorrent screen scrot w3m (with w3m-img )

Software that is not in the debian repos

Other

If you can watch small videos only, recode videos with: nice -n19 ionice -c3 mencoder -oac lavc -ovc lavc -lavcopts acodec=mp2:vcodec=mpeg2video:abitrate=128:autoaspect -of mpeg -vf scale=360:-2 -o small.mpeg big-source.avi

Make use of ionice (package util-linux). The CFQ has to be the active io scheduler in kernel (for kernel versions <5.0). Example: nice -n19 ionice -c3 aptitude update

A draft for reporting bugs by mail can be found at reportbug-by-mail