Excursus

OK, so there have been two recent posts about Skim, and while I was pleased to see this new entry to PDF viewers on Mac OS X, for every silver lining there is a dark cloud…

On the Sourceforge [tracker](http://sourceforge.net/tracker/index.php? func=detail&aid=1693191&group_id=192583&atid=941984), Andrea Bergia, PDFView’s developer, writes:

Hello, I am the developer of PDFView, an application which seems superseded by your wonderful Skim in many regards. I actually plan to use it as my default PDF reader…

This suggests that development of PDFView may halt.

This IMHO would be a bad thing. Here’s why.

pdfsync is technology that allows one to move back and forth between a LaTeX source and a PDF generated from it by pdflatex. Here is the description from the official pdfsync homepage:

pdfsync is an acronym for synchronization between a pdf file and the TeX or so source file used in the production process. As TeX system is not a WYSIWYG editor, you cannot modify the output directly, instead, you must edit a source file then run the production process. The pdfsync helps you finding what part of the output corresponds to what line of the source file, and conversely what line of the source file corresponds to a location of a given page in the ouput. This feature is achieved with the help of an auxiliary file: foo.pdfsync corresponding to a foo.pdf.

Being able to move effortlessly from PDF to LaTeX source and back again really speeds up the editing cycle. At this point I can’t imagine using LaTeX without it.

Unfortunately, Skim, unlike PDFView doesn’t support pdfsync. Indeed it might be incompatible with its note-taking features. Here is Michael McCracken, Skim and BibDesk developer, from the Skim mailing list:

Will Skim support pdfsync?

Meaning the ability to switch between LaTeX source and the rendered PDF? Not for the forseeable future.

The point of Skim is to create a great reader/note taker for existing

PDFs - there are already a lot of solutions for viewing PDFs you are working on, but in order to do a great job with a reader and note taker, we have decided not to support other uses that are already covered by existing apps.

In particular, because we are editing the PDF by adding annotations and extra notes, it creates a problem when you are also potentially regenerating the whole file using LaTeX. We can’t sync up without losing the notes.

So, Skim is a viewer, not a previewer.

But what are the alternatives?

TeXniscope is no longer under active development—indeed PDFView superseded TeXniscope incorporating some of its code. But PDFView may itself no longer be developed. TeXshop and iTeXMac are LaTeX IDEs that can be used with external editors, but I am happy with the LaTeX environment provided by my text editor, Textmate. There has been some talk by iTeXMac’s developer Jerome Laurens about breaking out the viewer, console, and editor as separate apps, but until that happens, there really is no other alternative that I know of.

A dark cloud indeed.