A virtual museum is a digital entity that draws on the characteristics of a museum, in order to complement, enhance, or augment the museum experience through personalization, interactivity and richness of content. Virtual museums can perform as the digital footprint of a physical museum, or can act independently, while maintaining the authoritative status as bestowed by ICOM in its definition of a museum. In tandem with the ICOM mission of a physical museum, the virtual museum is also committed to public access; to both the knowledge systems imbedded in the collections and the systematic, and coherent organization of their display, as well as to their long-term preservation.
As with a traditional museum, a virtual museum can be designed around specific objects (akin to an art museum, natural history museum), or can consist of new exhibitions created from scratch (akin to the exhibitions at science museums). Moreover, a virtual museum can refer to the mobile or World Wide Web offerings of traditional museums (e.g., displaying digital representations of its collections or exhibits); or can be born digital content such as net art, virtual reality and digital art. Often, discussed in conjunction with other cultural institutions, a museum by definition, is essentially separate from its sister institutions such as a library or an archive. Virtual museums are usually, but not exclusively delivered electronically when they are denoted as online museums, hypermuseum, digital museum, cybermuseums or web museums.
Pioneers (online before 2000)
The following online museums were pioneers. At that time, web pages were simpler, bandwidth was scarce, the concepts of the online museum were still developing, and there were limited multimedia technologies available within web browsers. Some online museums began in other (not web site) electronic forms, or were established by existing physical museums. Some online museums have become significant sources of scholarly information, including extensive citations within Wikipedia.
- Museum of Computer Art (MOCA) - Founded 1993. Directed by Don Archer, a non-profit corporation under charter from the Department of Education of New York State (US). MOCA was awarded .museum top-level domain (TLD) status by the Museum Domain Management Association (MuseDoma) in 2002 and is hosted on the Web.
- Web Museum, Paris — founded 1994, online 1994. A pioneering virtual or web museum is the Web Museum, created by Nicholas Pioch. It is hosted by ibiblio.
- The Lin Hsin Hsin Art Museum — online 1994. An early virtual art museum website by the Singaporean artist Lin Hsin Hsin.
- The Museum of the History of Science in Oxford — opened 1683, online 21 August 1995 - Located in one of the earliest purpose-built museum buildings in the world, the Museum was able to initiate a website relatively early because of the advantageous networking facilities and expertise available in their university environment.
- Ljubljana: Open-Air Museum — founded 1993 - online 1996. Ljubljana, the capital of Slovenia was presented as a huge museum where streets were the exhibitions of the architecture and building interiors were museum rooms. The method of the presentation were interactive maps and interactive Virtual Reality panoramas. . The aim of the project was to create "3D like" virtual visit of the museum and replacing and documenting the "reality" exhibition after it was discontinued in its original "reality form". After 1996, the project was extended to "Virtual museums of Slovenia", covering all country museums, that is over 106 museum exhibitions ,. Further development of the "Virtual museum"  developed to project City View documenting natural and cultural heritage of the country with over 10.000 locations until year 2006.
- Virtual Museum of Computing — founded 1994. This is an eclectic collection of links and online resources concerning the history of computers and computer science.
- Virtual Museum of New France — online 1997. Established by the Canadian Museum of Civilization Corporation.
- The Natural History Museum of Los Angeles County — founded 1910, online 1998. The museum is the largest natural and historical museum in the Western United States and an active research center.
- WebExhibits — founded 1999, online 1999. WebExhibits is an interactive, web-based museum that encourages visitors to think about and explore scientific and cultural phenomena in new ways. Exhibits include "Investigating Bellini’s Feast of the Gods," "Causes of Color," "Color Vision & Art," Pigments through the Ages," "Butter," "Van Gogh’s Letters," and "Poetry through the Ages," "Calendars through the Ages," and "Daylight Saving Time."
- The Science Museum in London — founded 1857, online 1999. One of the major science museums in the world was able to establish an early web presence partly due to the proximity of Imperial College, but was also spurred on by the fact that the Natural History Museum, which is next door, had recently established the first dedicated museum web server in the United Kingdom.
- The Thylacine Museum — online 1999. The Thylacine Museum is an online scientific and educational resource aimed at promoting a greater awareness and understanding of the biology, behaviour and history of the Thylacine, or Tasmanian tiger (Thylacinus cynocephalus).
- ibiblio — founded 1992, online 2000. An online exhibition with the backing of the Library of Congress, ibiblio hosted EXPO Ticket Office with exhibits including a Vatican Exhibit and even a virtual "restaurant" and "post office". This looks very simplistic now, but was novel in 1991.
Other online museums
Most physical museums now have an online presence, with varying degrees of online information. At one end of the spectrum, museums provide simple contact and background information, and a listing of exhibitions (brochure museums). On the other end of the spectrum are museums that exist only online, or those that have a physical building but offer extensive online exhibits, interactive online features, multimedia, and searchable or browsable collections (content museums, learning museums, virtual museums).
The following are a few other museums online:
- International Museum of Women is an online-only museum that does not have a physical building and instead offers online exhibitions about women's issues globally as well as an online community. Online exhibitions include "Imagining Ourselves" (launched 2006) about women's identity, "Women, Power and Politics" (2008), and "Economica: Women and the Global Economy" (2009).
- Girl Museum is an online-only museum that does not have a physical building and instead offers online exhibitions that celebrate girlhood in the past and present. Also offers educational guides, collaborative projects through social media, and a podcast series. Launched 2009.
- Tucson Gay Museum is an online-only museum that does not have a physical building and instead offers online exhibitions about LGBT history. The thousands of online photographic, audio, video, text, and other exhibitions include exhibits from the 1700s to 2012. The effort began in 1967.
- International New Media Gallery (INMG) is an online museum specialising in moving image and screen-based art. The INMG is dedicated to exploring current debates and topics in art history: touching on areas such as migration, war, environmental activism and the internet itself. The gallery publishes extensive academic catalogues alongside its exhibitions. It also hosts spaces for discussion and debate, both online and offline.
- Google Art Project is an online compilation of high-resolution images of artworks from galleries worldwide, as well as a virtual tour of the galleries in which they are housed. The project was launched on 1 February 2011 by Google, and includes works in the Tate Gallery, London; the Metropolitan Museum of Art, New York City; and the Uffizi, Florence.
- USAF Police Online Museum & Memorial – The USAF Police Alumni Association operates the USAF Police Virtual Museum & Memorial at www.usafpolice.org 
- Virtual Museum of Modern Nigerian Art — the VMMNA is the first of its kind in Africa. Hosted by the Pan-African University, Lagos, Nigeria this virtual museum offers a good view of the development on Nigerian Art in the past fifty years.
- UK's Culture24 — online guide to public museums, galleries, libraries, archives, heritage sites and science centres in the United Kingdom.
- Virtual Museum of Canada — Canada's national virtual museum. With over 2,500 Canadian museums, the VMC brings together Canada's museums regardless of size or geographical location.
- Museum With No Frontiers — launched its international website in 2007.
- Carnamah Historical Society - a West Australian community historical society with a small virtual museum.
- Museum of Perth - CyberMuseum using social media sites of Twitter and Facebook to tell the history of Perth, Western Australia, through photographs, videos and news feeds.  
Research and scholarship
The digitalization of museums is a task that has combined efforts, budgets and research from many museums, cultural associations and governments around the world. For the last few years, there have been projects related to Information Society Technologies dealing with: preservation of cultural heritage, restoration and learning resources. Some examples of contributions in the field of digital and virtual museography: Euromuse.net (EU), DigiCULT (EU), Musings, Digital Museums Projects. European Community has founded various projects to support this filed, like V-Must, the Virtual Museum Transnational Network that aims to provide the heritage sector with the tools and support to develop Virtual Museums that are educational, enjoyable, long-lasting and easy to maintain.
The leading international conference in the field of museums and their websites is the annual Museums and the Web conference.
In 2004, Roy Hawkey of King's College London reported that "Virtual visitors to museum websites already out-number physical (on-site) visitors, and many of these are engaged in dedicated learning".
In establishing virtuality and promoting cultural development, the goal is not merely to reproduce existing objects, but to actualize new ones. Information and communication technologies are not merely tools for processing data and making it available, but can be a force and stimulus for cultural development.
There are several types of interactive environments. One is to re-create 3D space with visual representations of the museum by a 3D architectural metaphor, which provides a sense of place using various spatial references. They usually use 3D modelling, VRML (Virtual Reality Modelling Language) and now X3D(successor to VRML) for viewing. There have been introduced various kinds of imaging techniques for building virtual museums, such as infrared reflectography, X-Ray imaging, 3D laser scanning, IBMR (Image Based Rendering and Modeling) techniques. In the case of EU-funded projects, the ViHAP3D, a new virtual reality system for scanning museum artifacts, has been developed by EU researchers. Another interactive three-dimensional spatial environment is QTVR. Being a pre-rendered, fixed environment it is more restricted in regards to moving freely around in 3D space but the image quality can be superior to that of real-time rendered environments. This was especially the case in the mid-1990s when computing power and online speeds were limited.
In 2013, the National Museum of Australia and the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) trialled a virtual museum tour system that uses mobile telepresence technology and requires a high-speed broadband connection. The technology allows remote visitors, for example school students from regional and remote Australia, to interact with a museum facilitator through a robot equipped with an omni-directional camera. Each remote visitor is able to control their own view of the museum gallery.
Museums have a variety of top-level domain names. In the USA, many are .org. Some are .gov, or governmental domains for other countries. A few are .edu in the USA, either as part of a larger educational institution, or grandfathered in when .edu regulations changed (e.g., as with the Exploratorium). The .museum domain name is used by some museums, as organized by MuseDoma, but is not widely used.
- Virtual Library museums pages
- Museology (also called museum studies), the study of how to organize and manage museums and museum collections
- Mobile museums — a different kind of mobile museum, when a museum is on an RV and drives to audiences
- Web Museum, Paris, ibiblio.org.
- Jonathan P. Bowen, Jim Angus, Jim Bennett, Ann Borda, Alpay Beler , Andrew Hodges, and Silvia Filippini-Fantoni, The Development of Science Museum Websites: Case Studies. In Leo Tan Wee Hin and Ramanathan Subramaniam (eds.), E-learning and Virtual Science Centers, Section 3: Case Studies, Chapter XVIII, pages 366–392. Idea Group Publishing, Hershey, USA, 2005.
- Jonathan P. Bowen, Jim Bennett, and James Johnson, Virtual Visits to Virtual Museums. In Jennifer Trant and David Bearman (eds.), Proc. Museums and the Web 1998, Toronto, Canada, 22–25 April 1998. CD-ROM, Archives & Museum Informatics, 5501 Walnut Street, Suite 203, Pittsburgh, Pennsylvania 15232-2311, USA, 1998.
- Jonathan P. Bowen, A Brief History of Early Museums Online, The Rutherford Journal, Volume 3, 2010.
- Michael Douma (2000). Lessons learned from WebExhibits.org: Practical suggestions for good design. In: Museums and the Web 2000. Proceedings. Ed. by David Bearman & Jennifer Trant.
- Schweibenz, Werner. "The Development of Virtual Museums". ICOMNEWS. no. 3. 2004.
- Girl Museum.
- Kennicott, Philip (2011-02-01). "Google Art Project: 'Street view' technology added to museums". The Washington Post, Arts Post. Retrieved 2011-08-25.
- "V-MUST: Virtual Museum Transnational Network; a EU FP7-funded Network of Excellence". Retrieved 2013-03-21.
- Hawkey, Roy (2004-09). "Learning with digital technologies in museums, science centres and galleries". Futurelab. Retrieved 2011-08-25. Check date values in:
- Elisa Giaccardi (2006). "Collective Storytelling and Social Creativity in the Virtual Museum: A Case Study". Design Issues 22 (3): 29–41.
- Mobile telepresence: National Museum of Australia
- Museum Robot: CSIRO
- 'CSIRO telepresence robots connect students with National Museum', Computerworld, 21 March 2013
- "virtual.museum" index, MuseDoma.