  The availability and easy access of large scale experimental and
computational materials data have enabled the emergence of accelerated
development of algorithms and models for materials property prediction,
structure prediction, and generative design of materials. However, lack of
user-friendly materials informatics web servers has severely constrained the
wide adoption of such tools in the daily practice of materials screening,
tinkering, and design space exploration by materials scientists. Herein we
first survey current materials informatics web apps and then propose and
develop MaterialsAtlas.org, a web based materials informatics toolbox for
materials discovery, which includes a variety of routinely needed tools for
exploratory materials discovery, including materials composition and structure
check (e.g. for neutrality, electronegativity balance, dynamic stability,
Pauling rules), materials property prediction (e.g. band gap, elastic moduli,
hardness, thermal conductivity), and search for hypothetical materials. These
user-friendly tools can be freely accessed at \url{www.materialsatlas.org}. We
argue that such materials informatics apps should be widely developed by the
community to speed up the materials discovery processes.
