Native applications for Windows XP, Windows Vista, Windows 7, and macOS were available, and for Linux, the Windows version was bundled with Wine compatibility layer.
'Picasa' is a blend of the name of Spanish painter Pablo Picasso, the word casa (Spanish for 'house') and 'pic' for pictures.
Picasa was a cross-platform image organizer and image viewer for organizing and editing digital photos, integrated with a now defunct photo-sharing website, originally created by a company named Lifescape (which at that time was incubated by Idealab) in 2002.