AmaLinks Pro - All-in-one WordPress plugin for Amazon affiliates
Ptable - Interactive periodic table with dynamic layouts showing names, electrons, oxidation, trend visualization, orbitals, isotopes, and compound search. Full descriptions from write-up sources.
IncludeWP - Top open-source frameworks for WordPress plugin & theme devs
Periodic-table.io - Interactive periodic table of the chemical elements in 38 languages - Includes properties, history, name origin, facts, applications, hazards, isotopes and more
Plugin Table - Periodic table of all the most popular WordPress plugins
Kalzium - Kalzium (German for: Calcium) is a periodic table of the elements for KDE SC 4.