For the moment I run Adobe Digital Editions under Wine to download ebooks burdened with ditigal restriction management. I only use it to open .acsm files supplied by ebook-shops, which contain authentication information required to download the actual DRM'ed ebook files, which I then transfer to my reader-device with calibre. My question is, if there exist open source alternatives to Adobe Digital Editions. They don't need much functionality. I just want to put the .acsm-file in and get the .epub out (no, I don't want to remove the drm, that'd be illegal afaik).