Miscellaneous

Open web link in browser

gx

Reverse lines in a range

:100,150g/^/m99

" reverses lines between 100-150
" works with visual selection too

Send escape in a command

<C-v><Esc> will print ^[ which will send escape in the command.

Join lines

Visually select the lines. :'<,'>j

Or, [range]j[lines]. eg. 5j20 would go to line 5, and join the next 20 lines.