In 2001, the “Journal of Machine Learning Research” was created in reaction to unadaptive publisher policies at MLJ. Essentially, with the creation of the internet, the bottleneck in publishing research shifted from publishing to research. The declaration of independence accompanying this move expresses the reasons why in greater detail.
MLJ has strongly changed its policy in reaction to this. In particular, there is no longer an assignment of copyright to the publisher (*), and MLJ regularly sponsors many student “best paper awards” across several conferences with cash prizes. This is an advantage of MLJ over JMLR: MLJ can afford to sponsor cash prizes for the machine learning community. The remaining disadvantage is that reading papers in MLJ sometimes requires searching for the author’s website where the free version is available. In contrast, JMLR articles are freely available to everyone off the JMLR website. Whether or not this disadvantage cancels the advantage is debatable, but essentially no one working on machine learning argues with the following: the changes brought by the creation of JMLR have been positive for the general machine learning community.
This model can and should be emulated in other areas of research where publishers are not behaving in a sufficiently constructive manner. Doing so requires two vital ingredients: a consensus of leaders to support a new journal and the willigness to spend the time and effort setting it up. Presumably, some lessons on how to do this have been learned by the editors of JMLR and they are willing to share it.
(*) Back in the day, it was typical to be forced to sign over all rights to your journal paper, then ignore this and place it on your homepage. The natural act of placing your paper on your webpage is no longer illegal.