The number of articles indexed on RePEc has recently surpassed half a million, with 88% linked to an online version. All these articles have been published in over 1000 journals listed on RePEc.
Journal articles now comprise the majority of the research material on RePEc, but this has not always been so. In fact, in the early days of RePEc, working papers (pre-prints) constituted the vast majority. But as commercial publishers started noticing how popular RePEc and its services were becoming, they wanted to be listed as well. They made the effort of converting their meta-data to our format and make it available at no charge. A few years back, this would have been unimaginable. Little by little, all major publishers opened RePEc archives. Nowadays, it is small independent publishers who join, along with various open access journals that look for free and efficient dissemination of their content through RePEc.