Comparative Index to Islam: Hagar (Ajar) 
Highlights differences between Islamic and Christian beliefs about the mother of Ishmael.
http://answering-islam.org/Index/H/hagar.htmlJewish Encyclopedia: Hagar 
Overview of Abraham's handmaid from the traditional Jewish perspective, including Talmudic commentary and a comparison with Islamic beliefs.
http://www.jewishencyclopedia.com/view.jsp?artid=53&letter=H
Yishmael and Hagar: A Perspective 
Rabbinic commentary on some of the questions raised by the story of Sarah's expulsion of her rival.
http://www.torah.org/learning/rabbis-notebook/5760/vayera.html
Hagar 
Biblical biography of the slave girl who bore Abraham's first son.
http://www.execulink.com/~wblank/20000820.htm
The Return of Hagar 
A Chassidic interpretation of the concubine, including the belief that Abraham married her after Sarah's death.
http://www.chabad.org/Parshah/Article.asp?AID=2636
Hagar, Mother of the Arab Nation 
A contemporary Baptist essay on the mother of Ishmael, concluding that the previously wicked woman was transformed after her encounter with an angel.
http://www.1timothy4-13.com/files/proverbs/art15.html
Jewish Virtual Library: Hagar 
Brief profile of the priest, with links to pertinent Torah passages.
http://www.jewishvirtuallibrary.org/jsource/biography/hagar.html