K-tree provides a scalable approach to clustering by combining the B+-tree and k-means algorithms. Clustering can be used to solve problems in signal processing, machine learning, and other contexts. It has recently been used to solve document clustering problems on the Wikipedia collection.
Paperless Office is a document management and electronic filing system. It is similar to Paperport, but adds many new features, such as automatic document classification, synchronization with your filing cabinet, date extraction, semantic Web integration, and sophisticated natural language processing, such as extracting todo lists from documents, spam detection, urgency classification, along with planning, scheduling, and execution features. You can set due dates and interdependencies for documents and tasks, so it has workflow support.
Mayan EDMS is a document manager Web application with custom metadata indexing, file serving integration, and OCR capabilities. It features user defined metadata fields, dynamic default values for metadata, lookup support for metadata, filesystem integration by means of metadata indexing directories, user defined document UUID generation, local file or server side staging file uploads, batch uploading of many documents with the same metadata, user defined document checksum algorithms, previews for a great deal of image formats including PDF, document OCR and searching, automatic grouping of documents by metadata, permissions and roles support, multi-page document support, page transformations, distributed OCR processing, and support for multiple languages.
MALODOS helps you to scan, store, and easily retrieve all your personal documents. Its storage format is open and documented, so your document archive can remain accessible even without MALODOS. The documents themselves are stored as standard PDF files, while their metadata (such as title, tags, and description) are stored into a separate SQLite database in an open format. With MALODOS, you can also manage existing files in PDF, JPEG, TIFF, and other formats, so you can still use the documents that you've already scanned. You can connect to any external OCR program to give access to a fulltext search feature.