Newly listed sites

English dictionary lookup with explicit usage guidance

Contemporary English lookup with vocabulary exercises

English definitions beside usage and collocation references

A multilingual dictionary portal

Regional history connected to Philadelphia's present

A subject-organized reference to Alabama

Reference articles on Georgia's history and culture

Animal reference searchable by information and media type

Amphibian reference with species and geography searches

Taxonomic lookup for living reptile species

Taxonomic and distribution information about algae

Bird taxonomy and regional checklists

Fish reference lookup by common or scientific name

Plant names linked to descriptions and distribution

Element information with history and periodic trends

Publication and authorship details for vascular-plant names

A maintained catalogue of marine taxonomic names

Taxonomic lookup for plants, animals, fungi and microbes

A species catalogue with explicit release distinctions

An interconnected reference for advanced mathematical ideas

A collaboratively written mathematics encyclopedia

Mathematician biographies and historical essays

An interactive periodic table with property and isotope views

Chemical reference data with documented data collections