Depending on the needs for your project, there are a variety of options for creating online exhibits. Iowa State University Library provides access to a variety of tools for creating online exhibits through Reclaim Hosting. Although you can get individual accounts through many of these, contacting DSI for access to the library’s subscription will often provide added benefits.
Omeka provides a web-based option for creating digital collections and media-rich online exhibits. Plugins are available which can provide added features to Omeka. A listing of available plugins is available here (including Neatline, a commonly used add-on for digital scholarship projects which allows for telling stories with timelines and maps). The ExhibitBuilder plugin is used to create online exhibits.
Scalar is a Non-linear web-based publishing platform that allows for creating media-rich, flexible and interactive publications including online exhibits.
Wordpress can be used to create a website, blog, or app. Themes, plugins, and widgets provide users with a variety of options. Free and paid options available.
Madoc is a platform using the International Image Interoperability Framework (IIIF) to display and curate digital objects from across IIIF supported collections.
CollectiveAccess is a web-based cataloging and online publishing platform for library, museum, and archive projects.
Knight Labs Storytelling Tools allow users to tell stories through maps, timelines, panoramic images, sound, and other options.
MediaWiki is a tool to create simple wiki-like websites, presentations, and online exhibits.
Drupal is a free, open-source web content management framework. It can be used to create online exhibits with plugins for sliders, banners, galleries, and interactive components.