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GitHub User: mouton-rebelle
There are 2/3 differents concept in your comment :
Twitter Bootstrap for example uses Less by default, but there are fork that works with Sass.
Blueprint is also available as a Compass module : if you import compass/sass, you get a whole lot of mixin to generate blueprint css that suits your need. You can also make a fluid grid layout with these, just like with Twitter Bootstrap.
I love Sass/Compass, and I am currently trying Twitter Bootstrap on a project.