Ever growing number of research funders demand that research publications that can be attributed a specific research project that they fund must be made openly available either by self-archiving or publishing in an Open Access journal. The idea is that publicly funded research should be openly, freely and publically available and accessible. There are many ways to publish Open Access and many research funders ha special funds to finance Open Access publishing.
Demands for Open Access publishing comes both from Swedish research funders but also international funders. European Commissions Seventh Framework Programme (FP7) is an example for this. The American National Institutes of Health (NIH) requires Open Access. Horizon 2020, the next framework programme from EU is planning on requiring Open Access.
Example on other research funders who require Open Acces are (mostly in Swedish):