I tried to change the syntax highlighting, by copying /usr/share/vim/vim74/syntax/html.vim to ~/.vim/after/syntax/html.vim. Then I changed the syntax highlighting file, but I don't see any changes. filetype is set properly, and when I change something in /usr/share/vim/vim74/syntax/html.vim, I can see the changes. Is there anything I need to do to activate the after/syntax folder for highlighting?
Personal syntax highlighting
syntax highlighting
To change the syntax highlighting of a filetype by copying $VIMRUNTIME/syntax/<filetype>.vim to your ~/.vim directory, the proper place to copy it is ~/.vim/syntax/, not ~/.vim/after/syntax/. Vim will then use your syntax file instead of the one in $VIMRUNTIME/syntax.Your ~/.vim/after/syntax/ directory is the proper place for files that make relatively small tweaks to the syntax highlighting, such as changing the colors of highlight groups. The problem with making major changes in the ~/.vim/after/syntax/ directory is that the behavior of some of Vim's syntax rules depends on the order in which the rules are executed, and any rules in ~/.vim/after/syntax are going to be executed after the rules in $VIMRUNTIME/syntax.I think the reason that the changes you make to ~/.vim/after/syntax/html.vim are not showing up is because of this line near the bottom of $VIMRUNTIME/syntax/html.vim,let b:current_syntax = htmland this block at the top of $VIMRUNTIME/syntax/html.vim, which is presumably still in your copy in ~/.vim/after/syntax/html.vim:if !exists(main_syntax)  if version < 600    syntax clear  elseif exists(b:current_syntax)    finish  endif  let main_syntax = 'html'endifThat block is detecting that b:current_syntax has already been set, so it terminates the script at that point by executing finish. None of your changes to that file are being executed.