Context: English Bible Translations
The English Standard Version (2001) is a revision of the Revised Standard Version of the Bible, by a group of over 100 evangelical scholars headed by James I. Packer.
Its translation style follows the New American Standard Bible in using "formal equivalence" (i.e. word-for-word) rather than "dynamic equivalence". Nevertheless, it seeks to render the translations in more readable English (unlike the NASB). In the end it sits somewhere between the NASB and the NIV in its literalness.
Of particular interest is that although the ESV follows the RSV in its translation tree, the translation replaces the more liberal elements of the RSV with more conservative ones. Thus "expiation" in the RSV is replaced with "propitiation", placing emphasis on the wrath of God being dealt in the atonement.
More (official) information on the ESV can be found at http://www.gnpcb.org/EN/Product/esv_story/.