ChOX
ChOX (short for Chemical Object Explorer) is a handy GUI tool for browsing the contents of chemical structure and reaction data files.
Key Features
Can handle large files containing millions of molecules/reactions without memory or performance issues
Performs 2D structure layout on-the-fly if required/desired
A large array of structure/reaction visualization settings
Allows the selection of individual entries for export or printing
A wide panel of supported input and output file formats