The Aramaic Targum of Isaiah is an incredibly important resource for the study of ancient biblical interpretation. It is particularly relevant to the study of the Old Testament in the New, because many of its readings/interpretations of the Hebrew text appear to inform, parallel, or be reflected in the New Testament. Accordance, BibleWorks, and Logos all have tagged Targum texts available. English translations are a bit harder to obtain. As far as I can find, Logos does not have any such translations available. BibleWorks contains the old Etheridge translations of the Pentateuch targums and Cook's translation of the Psalms Targum. Accordance is particularly notable for commissioning their own translation by Eldon Clem. In addition to the Pentateuch targums, they also have ones for Targum Jonathan to Joshua, Judges, 1 & 2 Samuel, Hosea. (I am under the impression that this translation project is ongoing, so more texts may be coming.)
- For online Aramaic texts, check the Comprehensive Aramaic Lexicon.
- The Etheridge translations of the Pentateuch targums are at NTCS. (Note the links to English translations to the targums on Lamentations, Ruth, and Psalms as well.)
- You can get the targumim--both Hebrew and English--for the Palm operating system HERE.
The good news here is that Jay Palmer has converted it into a module that can be integrated into BibleWorks. It's posted on the BibleWorks blog. Thanks!