According to The Oxford Companion to Archaeology:
The biblical manuscripts from Qumran, which include at least fragments from every book of the Old Testament, except perhaps for the Book of Esther, provide a far older cross section of scriptural tradition than that available to scholars before. While some of the Qumran biblical manuscripts are nearly identical to the Masoretic, or traditional, Hebrew text of the Old Testament, some manuscripts of the books of Exodus and Samuel found in Cave Four exhibit dramatic differences in both language and content. In their astonishing range of textual variants, the Qumran biblical discoveries have prompted scholars to reconsider the once-accepted theories of the development of the modern biblical text from only three manuscript families: of the Masoretic text, of the Hebrew original of the Septuagint, and of the Samaritan Pentateuch. It is now becoming increasingly clear that the Old Testament scripture was extremely fluid until its canonization around A.D. 100

Just in case you are in the "Dead Sea Scrolls support non-change" camp.

Just saying