What is American Law Institute?

Legal Definition
The American Law Institute (ALI) was established in 1923 to promote the clarification and simplification of United States common law and its adaptation to changing social needs. Members of ALI include law professors, attorneys, judges and other professionals in the legal industry. ALI writes documents known as "treatises", which are summaries of state common law (legal principles that come out of state court decisions.) Many courts and legislatures look to ALI's treatises as authoritative reference material concerning many legal issues. However, some legal experts such as Professor Michael Risch of Villanova Law School and the late Supreme Court Justice Antonin Scalia have voiced concern about ALI rewriting the law as they want it to be instead of as it is.

The ALI drafts, approves, and publishes Restatements of the Law, Principles of the Law, model codes, and other proposals for law reform. The ALI is headquartered in Philadelphia, Pennsylvania.

At any time, ALI is engaged in up to 20 projects examining the law. Some current project have been watched closely by the media, particularly the revision of the Model Penal Code Sexual Assault provisions.
-- Wikipedia
Legal Definition
a non-profit organisation with the main objective of defining and clarifying common law principles existing in our country.