Periodic-table.io - Interactive periodic table of the chemical elements in 38 languages - Includes properties, history, name origin, facts, applications, hazards, isotopes and more
Ptable - Interactive periodic table with dynamic layouts showing names, electrons, oxidation, trend visualization, orbitals, isotopes, and compound search. Full descriptions from write-up sources.
Kalzium - Kalzium (German for: Calcium) is a periodic table of the elements for KDE SC 4.
Gnome Chemistry Utils - The Gnome Chemistry Utils include six chemistry related programs:
GPeriodic - GPeriodic is a periodic table application for Linux.
Atomic - Periodic Table - Bring a Periodic Table with you anywhere you go