To cite one glaring gap: Although there are now more than 6,500 names on the list of artists (cumbersomely alphabetized by first name, with no option to reconfigure by last name), the site still does not include a single work by Picasso. There is also apparently nothing by Georges Braque, Marcel Duchamp, Kazimir Malevich or Max Beckmann and only a single painting by Matisse, thanks to the Toledo Museum of Art. Postwar American and European art fares no better; none of the main Abstract Expressionists are represented. No Beuys, Fontana or Manzoni. Nothing notable by Johns, Rauschenberg or Warhol (although the Art Institute of Chicago has managed put up a very nice 1961 painting by Twombly).

But that will undoubtedly change. One of the glories of the Google Art Project is that it is a collective, additive work in progress that allows any museum or art-related organization to join and upload as many — or as few — high-resolution images of artworks as it chooses. At some point some museum somewhere is going to tackle the Picasso rights problem.

In the meantime the grand potential of the project and of its collaborative structure is fully evident in the new version. In all, it ranges through several millenniums of art history and also across actual space in ways that boggle the mind, and it ushers in a new era of interconnected access both to world art and among the institutions that preserve it. It is light-years beyond the first version, which had its debut early last year and featured 17 participating museums from Europe and the United States and a selection of just over 1,000 works in a single medium — painting — that represented but a few centuries of Western art.

At the time the air was thick with wait-and-see caution. Now museums large and small from around the globe have jumped aboard, joining early adopters like the Metropolitan Museum of Art, the Museum of Modern Art, the Gemäldegalerie in Berlin and the National Gallery, London.