||This article appears to be written like an advertisement. (October 2011)|
|Type||Web application framework|
Frontend technologies 
As any web application XPages applications can use REST services. XPages also provides easy mechanisms to bind data sources to UI controls so that for many scenarios no code needs to be written. Additionally XPages allows to declaratively only refresh parts of the page via Ajax when submitting data.
Backend technologies 
In order to access data, XPages and Domino Designer use data sources. These data sources can be bound graphically to UI controls on pages. UI controls and other types of controls show up in a palette of controls in Domino Designer and can be dragged and dropped onto pages. Domino Designer also comes with further convenience functionality, such as field validations and translations. XPages functionality can be modularized in Custom Controls which are XPages controls that can be reused in multiple XPages pages and parametrized based on context.
The XPages runtime can be extended using the Extensibility API which is based on JavaServer Faces. This capability can for example be used by ISVs who want to provide their own libraries of XPages controls.
Storage: Document-oriented Database 
The XPages runtime is part of IBM Lotus Domino and leverages the proven and mature capabilities Domino provides. Domino uses a document-oriented database called NSF (Notes Storage Facility) to manage semi-structured data like rich text and files. The data is stored as documents and views allow finding specific documents efficiently. Documents have unique ids and further built in fields like the last author, last modified date, etc. and they have custom application specific fields. Documents can contain rich text which can be formatted text and images (MIME) or full file attachments. Documents can be queried via APIs and views. Lotus Domino also supports full text search for a full database as built in feature.
XPages applications can easily be deployed on Domino servers or a cluster of Domino servers using IBM Lotus Domino Administrator and more precisely the replication/synchronization mechanism built into IBM Lotus Domino. The replication mechanism supports bi-directional conflict detection and resolution in distributed environments.
XPages applications and the document oriented database can be secured in multiple ways. There is a so called ACL (access control list) which contains a list of users, groups and roles and their access rights. Security can furthermore be applied on document level via reader and author fields. On top of the default ACL of the notes database ACL's can be applied to separate xpages as well.
Adding an ACL to a separate xPages defines who can access / run the specified XPage.
The XPages development community manages the website XPages.info with various types of information about XPages, including how to get started, downloads, resources and demos.
The origins of XPages technology can be traced as far back as year 2000, when Trilog Group, an IBM Business Partner, invented a component-oriented rapid web application development model, called XSP, similar to the Domino RAD model, but based on J2EE, XML and open standards. In August 2004, IBM acquired the XSP technology assets from Trilog Group in an effort to offer a RAD tool for IBM Workplace that is similar to Domino Designer.
The XPages technology, based upon JSF and J2EE, started life at IBM, from 2005 to 2007, inside the now discontinued IBM Lotus Workplace Designer and subsequently IBM Lotus Component Designer under the code name 'XFaces'. In mid 2007, the XFaces technology became 'XPages' and adopted by IBM Lotus Notes Domino, incorporated in the development cycle for the 8.5 release. XPages was previewed at Lotusphere 2008 (AD303 Transforming IBM Lotus Domino Web Apps with IBM Lotus Domino Designer Speakers: Rocky Oliver, Martin Donnelly). IBM Lotus Notes Domino 8.5 was released in December 2008 and in time for Lotusphere 2009 where it was one of the many highlights of the show.
IBM Lotus Notes Domino 8.5.1 continued the development of the XPages technology including the running of XPages applications inside the Notes Client. This release also included several improvements to performance and UI which helped XPages applications perform and scale better. IBM Lotus Notes Domino 8.5.2 contained many more improvements and additions to the feature set of XPages.
The 'XPages' name was inspired from the original XSP naming idea, where XSP was actually an acronym for 'XML Server Pages'. After a first rebranding of XSP to 'XFaces', IBM chose 'XPages' as the project code name for the pre-release technology included in Domino Designer. With a catchy alternative being hard to come by, the project name stuck.
- "Make your XPage Apps "Pop!" withCSS and Themes"
- OneUI theme
- Dojo toolkit
- APIs reference
- XPages Extensibility API
- The document oriented database is a core part of the Domino architecture. Note that these two referenced PDF documents are old but still give a good overview of the fundamental concepts.
- Java classes A-Z
- XPages.info - Rapid Web and Mobile Application Development Platform
- OpenNTF.Org - Open Source Site for IBM Lotus Domino
- Notes and Domino Application Development wiki
- Lotus Notes and Domino home page
- Product Documentation
Further reading 
Martin Donnelly, Mark Wallace and Tony McGuckin. (2011). Mastering XPages: A Step-by-Step Guide to XPages Application Development and the XSP Language. IBM Press. ISBN 0132486318