For our June “Staff Pick” Project of the Month, we selected Skim, a PDF reader and note-taker for OS X.
Skim is designed to help you read and annotate scientific papers in PDF, but is also great for viewing any PDF file. It offers plenty of great features, including one-swipe highlighting, notes, snapshots and more.
We caught up with Skim developer Christiaan Hofman as he shared some thoughts about the project’s history, purpose, and direction.
SourceForge (SF): Tell me about the Skim project please.
Christiaan Hofman (CH): Skim is a PDF viewer for the macOS. It is mainly directed towards researchers who read a lot of PDF papers and are used to making notes on these papers, which we try to make easier on the computer to avoid having to print them out. But with this intended use came a lot of other features, in particular inspired by the experience of researchers. For instance, when they need to make presentations, help writing papers with tex, need automatic scrolling for reading, etc.
SF: What made you start this?
CH: Skim started out of the development of BibDesk, a citation manager app, that also manages files. I must say that the project was started by Michael McCracken, and developed in collaboration with Adam Maxwell. To have a better experience reading papers that were linked in BibDesk we thought it would be better to create a stand alone PDF viewer rather than extending the built-in viewer capability of BibDesk. The main idea behind Skim is to have the experience researchers have reading papers on physical paper to the computer. This experience involves tacking on post-its on the pages, circling and highlighting pieces of text, and margin notes. This is what we tried to move to a PDF viewer app.
SF: Has the original vision been achieved?
CH: I do think this has been achieved. And in fact much more, as we have added support for presentations, interaction with tex generation, and many more features. Of course this question can best be answered by our users.
SF: Who can benefit the most from your project?
CH: Skim was developed in particular with academic researchers in mind. So they could benefit most from Skim. However, it may very well be used by any Mac user to view PDFs, which of course everybody does. And I think it can compete against the built-in Mac viewer Preview, at least that is what some of my users say.
SF: What core need does Skim fulfill?
CH: As I said mostly viewing PDFs, and making notes on the PDF. Due to the way skim saves the PDF, the original PDF without the attached notes can be easily recovered.
SF: What’s the best way to get the most out of using Skim?
CH: This depends very much on the user. But it can really help to figure out a lot of things that may not immediately be obvious and that can make life easier. For instance by checking the Skim Wiki page on SourceForge.
SF: What has your project team done to help build and nurture your community?
CH: We maintain the users’ mailing list, as well as the bug and feature request trackers, and the Wiki pages.
SF: Have you found that more frequent releases helps build up your community of users?
CH: We have not really tracked this, but I think it does. New releases also trigger notifications at various software update sites, that can draw attention to Skim. It also helps if bugs are fixed quickly.
SF: What was the first big thing that happened for your project?
CH: Getting a working viewer and allowing to model the note taking is of course the core of Skim. And we had to decide about how to save the data of the notes, for which we had to be innovative. When that worked, we had the basis of the app.
SF: What do you think helped make that happen?
CH: We built the app around Apple’s PDFKit framework to view PDFs. At the time, in 2007, this was still somewhat limited, that’s why we had to be innovative in saving the data.
SF: How has SourceForge and its tools helped your project reach that success?
CH: We could easily collaborate on the project, brainstorm on the developer mailing list, and collaborate on development through the svn support. We already had experience with that because of the BibDesk project, also on SourceForge. Also, SourceForge provides us with the infrastructure to reach our community through the mailing lists, the Wiki, and release system.
SF: What is the next big thing for Skim?
CH: At the moment I don’t really have any big new features planned for Skim. The last few years I have been mainly busy with maintaining the project, fixing bugs and adding small features. Although I must say that in the last few months I did add a few bigger features, such as a reading pacer, an overview feature, and saving forms in our note data. So for now I will maintain the project and keep a lookout for bugs to fix.
SF: Do you have the resources you need to make that happen?
CH: SourceForge allows me to track bugs and let users submit feature requests. If there is anything worthwhile suggested, I may take that up. But of course the biggest resource, especially for a non professional project like Skim, is time. And that is often in short supply.
SF: If you had to do it over again, what would you do differently for Skim?
CH: The most important thing I would do differently is the format we use to save the data. This format unfortunately is not compatible with iOS, so Skim cannot be ported to the iPhone and iPad. When we started Skim, these did not exist yet, so we did not foresee the incompatibility. So in hindsight we could have used a slightly different and more universal data format for the notes.
SF: Is there anything else we should know?
CH: For further development of Skim we could always use input, in particular for more developers to maintain and further build on Skim.
[ Download Skim ]
looks good