The Resurgence Greek Project not only offers the text of the Septuagint (LXX) but has programmed parsing and simple translation information on mouse-over. Check it out! Though it may not be the best manuscript, this is by far the best web-based original language tool that I’ve found.
Other resources off the top of my head are GreekBible.com, Unbound Bible at Biola, Strong’s Lexicon, Online Greek Interlinear Bible, Jonathan Robie’s Biblical Greek Resources, Brown-Driver-Briggs online, and the NT Gateway with many more links.
So, even if you are away from the tools in your library or on your personal computer, you can do in-depth study from any computer with web access.
edit: Also check out the Online Critical Pseudepigrapha