Over the past decade, new innovations have transformed the Transmission Electron Microscope (TEM) from a high-resolution image acquisition tool into an in situ nanoscale materials R&D laboratory. The Protochips Atmosphere system combines chemically inert MEMS-based heaters and a closed cell holder design to introduce realistic gas environments safely inside the TEM for applications ranging from heterogeneous catalysis to nanostructure nucleation and growth. Atmosphere allows atomic-scale resolution at gas pressures up to 1 atm and sustained temperatures up to 1000°C, while retaining full EDS and EELS analysis capabilities. Protochips also offers complementary software and hardware solutions for in situ heating, electrical, liquid, and gas experiments to expand any TEM into a state-of-the-art in situ laboratory.