docs: general introduction to invenio
Introduction
============
+
+Invenio is an open source framework for building large-scale digital
+repositories.
+
+A framework
+-----------
+Invenio is first and foremost a framework. It's a framework that you can use
+to build a turn-key repository solution, but it is not by itself a final
+turn-key repository software. Using Invenio requires you to develop code.
+
+Several repository software solutions are in the progress of being written on
+top of Invenio, including e.g.:
+
+- RERO ILS and Invenio ILS - Integrated Library System.
+- WEKO3 - Repository infrastructure for 500+ japanese universities.
+
+Several repositories have been built on top of Invenio v3, including e.g.:
+
+- Zenodo - General purpose research data repository.
+- CERN Open Data - Open data repository for CERN.
+- CERN Videos - Digital Assets Management system with video encoding support.
+
+Scalability & Safety
+--------------------
+Two of the main strengths of Invenio is the scalability and safety. Invenio is
+built to run on anything from a single machine to clusters of 100s of machines,
+to handle 100 records or 100 million records as well as to handle a 1 megabyte
+or a 1 petabyte.
+
+That's why we say Invenio is a framework for large-scale digital repositories.
+Often, large-scale repositories does not fit in a standard box, which is why
+Invenio is first and foremost a framework, that helps you build your repository
+faster and on a high-quality reliable foundation.
+
+Flexible metadata
+-----------------
+In its core, Invenio provides you with a flexible record and persistent
+identifier store capable of handling 100 millions of records. Records can
+use existing metadata formats such as JSON-LD, MARC21, DublinCore, DataCite, as
+well as your own custom or derived metadata format. Invenio easily handle
+multiple types of records such as bibliographic records, authority records,
+people, grants, funders, books and photos to name a few.
+
+Internally Invenio natively store records as JSON documents whose structure
+can be validated and described with JSONSchemas. Records can easily be linked
+via JSONRef providing you with powerful tools to model your records. Invenio
+further comes with robust metadata transformation layer that can serialize
+records to e.g. MARCXML, DataCite XML, JSON-LD, Citation Style Langauge (CSL)
+JSON and many other formats.
+
+In addition Invenio provides a persistent identifier store and a resolver
+that allows you to use your preferred persistent identifier scheme for
+identifying records such as DOIs (Digital Object Identifiers), Handles, PURLs,
+URNs or your own local identifier. The persistent identifer resolver further
+has support for advanced features such as tombstone pages, redirection and
+merged records.
+
+Powerful search
+---------------
+Under the hood, Invenio uses Elasticsearch, the world's most popular open
+source search engine that provides powerful distributed and massively scalable
+search engine. Invenio provides all the features of Elasticsearch such as
+full-text search, powerful query syntax, advanced stemming and aggregations,
+super-fast auto-completion suggesters as well as geographical search.
+
+Invenio further leverages both instant indexing as well as extremely fast
+distributed bulk indexing with rates beyond 10,0000 records/second.
+
+File management
+---------------
+Invenio handles both millions of files and petabytes of data. Invenio provides
+natively on object storage REST API that concurrently can use multiple
+underlying storage systems such as S3, XRootD, NAS, WebDAV.
+
+The file store further handles integrity checking according to desired
+schedules and supports even checking close to 1M files in less than an hour
+if your storage backend can support it.
+
+The file store further comes with quota management that allows you detailed
+control of max file sizes and upload limits.
