here's a few tweaks I made to Benjamin Ferrari's version:

• the search-forward-regexp didn't specify an end, so it would operate on stuff from beginning of region to end of buffer (instead of end of region)
• Now increments end properly, as Cheeso noted.
• it would insert a break between <tag></tag>, which modifies its value. Yes, technically we're modifying values of everything here, but an empty start/end is much more likely to be significant. Now uses two separate, slightly more strict searches to avoid that.

Still has the "doesn't rely on external tidy", etc.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; pretty print xml region (defun pretty-print-xml-region (begin end) "Pretty format XML markup in region. You need to have nxml-mode http://www.emacswiki.org/cgi-bin/wiki/NxmlMode installed to do this. The function inserts linebreaks to separate tags that have nothing but whitespace between them. It then indents the markup by using nxml's indentation rules." (interactive "r") (save-excursion (nxml-mode) (goto-char begin) ;; split <foo><foo> or </foo><foo>, but not <foo></foo> (while (search-forward-regexp ">[ \t]*<[^/]" end t) (backward-char 2) (insert "\n") (incf end)) ;; split <foo/></foo> and </foo></foo> (goto-char begin) (while (search-forward-regexp "<.*?/.*?>[ \t]*<" end t) (backward-char) (insert "\n") (incf end)) (indent-region begin end nil) (normal-mode)) (message "All indented!")) 

here's a few tweaks I made to Benjamin Ferrari's version:

• the search-forward-regexp didn't specify an end, so it would operate on stuff from beginning of region to end of buffer (instead of end of region)
• Now increments end properly, as Cheeso noted.
• it would insert a break between <tag></tag>, which modifies its value. Yes, technically we're modifying values of everything here, but an empty start/end is much more likely to be significant. Now uses two separate, slightly more strict searches to avoid that.

Still has the "doesn't rely on external tidy", etc. However, it does require cl for the incf macro.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; pretty print xml region (defun pretty-print-xml-region (begin end) "Pretty format XML markup in region. You need to have nxml-mode http://www.emacswiki.org/cgi-bin/wiki/NxmlMode installed to do this. The function inserts linebreaks to separate tags that have nothing but whitespace between them. It then indents the markup by using nxml's indentation rules." (interactive "r") (save-excursion (nxml-mode) (goto-char begin) ;; split <foo><foo> or </foo><foo>, but not <foo></foo> (while (search-forward-regexp ">[ \t]*<[^/]" end t) (backward-char 2) (insert "\n") (incf end)) ;; split <foo/></foo> and </foo></foo> (goto-char begin) (while (search-forward-regexp "<.*?/.*?>[ \t]*<" end t) (backward-char) (insert "\n") (incf end)) (indent-region begin end nil) (normal-mode)) (message "All indented!"))