ECOLEX is a free online database specializing in environmental law. The coverage is global in nature, and is operated jointly by the Food and Agriculture Organization, International Union for Conservation of Nature, and United Nations Environment Programme.
The database includes treatises, guidance documents, legislation, judicial decisions, and literature. Per its website, “[u]sers have direct access to the abstracts and indexing information about each document, as well as to the full text of most of the information provided.”
The site offers a simple search interface or an advanced search option. Using the advanced search, researchers can refine their search by type of material (e.g. court decisions or legislation), date, subject, language, geographic area, and keywords. The one item I wish was included (or I completely missed it) is an option to limit the results to only full text items.