EPiServer CMS is a Web Content Management product based on .NET for general website development and management. It includes all the features standard to any CMS, including template management, workflows, page management and, by definition, content management.
It is similar to Sitecore in the sense that most of the actual page layout design is done externally using ASP.NET (usually with Visual Studio). But, unlike Sitecore, there is no decoupling of data from the page templates. This means that the content fields, or properties in EPiServer parlance, always exist inside a Page Type (equivalent to the Data Template in Sitecore), but each Page Type is assigned one layout (an ASPX page).
In EPiServer, Page Types are coupled to a layout (ASPX page)
and each Page Type has its specific Properties (content fields).
In Sitecore, any Data Template can be assigned multiple layouts, effectively decoupling the presentation from the data. To achieve a similar effect in EPiServer, the ASPX page must be coded to handle the different presentations for the related Page Type.
In Sitecore, Data Templates are defined separate of the presentation, with their respective content fields
and Layouts can be assigned separately, for multiple devices if needed.
When creating a site structure, it does it like RedDot CMS in SmartTree mode, with a tree of pages that are instances of Page Types. Each page is part of the Navigation Structure, but they can be manually excluded from it.
Content Tree in EPiServer Edit Mode
Content Tree in Sitecore Content Editor
Editing of content is done in a similar fashion to the Content Editor of Sitecore, or the Form Editing mode in RedDot.
Content Editing in EPiServer Edit Mode.
Content Editing in Sitecore Content Editor.
There is also a visual editing mode similar to the inline page editor of Sitecore or SmartEdit mode in RedDot (though not as complex and customizable as SmartEdit), recommended for fast edits and corrections.
Content Editing in EPiServer View Mode.
Content Editing in Sitecore Page Editor.
After each edit and release, EPiServer keeps track of all versions of the page, and any version can be published whenever needed (ideal for rollbacks). Also, it handles very smoothly deferred publishing and page expiration, the user only sets the dates and times of these events for each page.
Multi-lingual support is built into the product. Pages can have content in different languages, and there is an option of displaying pages in a specific rollback language if the content doesn't exist in the selected language. Workflows can be configured to notify translators of content ready for translation.
All workflows in EPiServer are based in Windows Workflow Foundation (WF). The product provides some pre-defined events to handle the majority of the requirements of clients, but since it's based in WF, workflow functionality can be extended as needed.
For developers, EPiServer provides a full .NET API and, unlike Sitecore, it also provides a set of controls for ASP.NET and a Visual Studio plug-in. The Visual Studio integration plug-in provides templates for EPiServer projects, page types, user controls, custom property types and GUI plug-ins (plug-ins for the Admin and Edit modes of EPiServer). The ASP.NET control set includes general controls to render page content, menus, retrieve data collections, make news lists, and more.
EPiServer offers separate modules for Social Media and Marketing purposes. EPiServer Community is a platform that allows the creation and management of online communities. EPiServer CMO (Campaign Monitor and Organization) is a module that connects as a plug-in to CMS, and provides tools to test, measure, analyze and monitor online marketing campaigns. EPiServer SEO is a module that is also a plug-in for CMS, and provides tools for Search Engine Optimization. It includes tools that help webmasters fine-tune keywords, URLs, link placement, and even a calculation for Google PageRank. EPiServer Business-to-Business (B2B Prospect and B2B Adapt) provides tools to track visitors to the website, including geo-location and follow-up of potential business relations.
Support to clients and partners is provided through the EPiServer World website. It includes blogs, forums, documentation, and general help in any of the products provided by the company.
In conclusion, EPiServer is a complete Content Management solution, includes all the tools to manage and deploy complex websites, and since it's based in .NET 3.x technology, it can be easily extended and even integrated into other .NET solutions. The main disadvantages are that it can only reside in Windows-based servers, requires SQL Server or Oracle database, templates can only have one presentation (although it can be worked-around with code), and it needs some fine-tuning for performance on production environments (although this is an issue on most CMS products).