KOSHER vs. HALAL
To understand both you must first know the history of it's origin. Kosher has been around for thousands of years. Since Moses brought the Torah down on mount Sinai. Halal although been around for awhile, only became main stream in this millennium.
For hundreds of years the Jews and Muslims lived in peace and harmony in the Arab world. Many Muslims bought there meat from Jewish store owners. In 1945 with the creation of the Jewish state of Israel, turmoil began between Jews and Arabs, who were mostly Islamic.
With the TV explosion of the 70's, brought the the political views of the Arab government to the Muslim people, and violence against Jews began to get out of hand. It is then the western world brought pressure to bear on the Arab countries to release the Jews. The 80's saw a mass exudes of the Jewish people to other countries, which left a void in the meat market, in those countries... and so Halal began to form.
Halal was created in the image of Kashrus, although there are differences.
The 90's saw Muslims moving to European and Western countries, and Halal came with them, and became main stream in the early millennium.
I can list the requirements of both, but there is plenty of information on the internet for that, I'd like to focus on the differences.
Both use animals which eat plants, and no animal which eat meat may be used, however there are slight differences, for instance Halal allows Rabbits, and Camels. Kosher doesn't
Both demand the animal be healthy, but that is a U.S government standard today, so all slaughter houses most use that standard, and many other countries who do business with the U.S hold those standards.
Kosher slaughter begins with the blessing of GOD, and the individual must have in mind for all subsequent animal are included in the first blessing, while Halal must revoke the name of GOD for each animal.
Neither can eat the blood of the animal, however Kashrus goes a step further by soaking and salting the meat to draw out as much blood as possible, while Halal only focuses on the veins where blood is held. Furthermore Kashrus demand blood be spilled on the ground, while Halal permits the blood to be used further, for medicine or research.