For canned packages, of the ones I’ve personally tried, were I trying to implement workflow…mambo is free and open source. It has workflow built-in. For me it has been somewhat difficult to get my mind around but serves me well for a small club site.
I’m in the process of attempting to migrate another club site to Expression Engine by pMachine. It’s an odd mix of “incredibly good” and “I can’t believe they didn’t implement that by default” – it has all the pieces to support workflow but you need to do some configuration to define and build it in yourself. I hate it when something is stopping me from moving forward, but usually love it the minute I suss it out. It costs big-time but I did in fact upgrade a pMachine Pro license to ExpressionEngine and don’t seriously regret it I use pMachine Pro on serveral other sites, including my personal site, but workflow isn’t really its thing. It’s great for a personal site, and there’s pMachine Free if you’re only needing a single ‘blog’. I could easily see it being used for a repository of technical papers. It’s ‘bloggish’ in concept but with easy template editing it can be made to appear much like a ‘static’ site.
Both mambo and pMachine have very good communities supporting them.