DSpace at MIT
DSpace is a digital repository created to capture, distribute and preserve the intellectual output of Massachusetts Institute of Technology. Over 10,000 items are currently available including preprints, technical reports, working papers, conference papers, images, and more.
https://dspace.mit.edu/


Directory of Open Access Journals (DOAJ)
The Directory of Open Access Journals service covers free, full text, quality controlled scientific and scholarly journals.  Over 120 Engineering and Technology journals are covered and approximately 2500 articles currently available.  Perx indexes only the Engineering and Technology sections of DOAJ.
http://www.doaj.org/


Australian Research Repositories Online to the World (ARROW)
The ARROW discovery service provides access to scholarly materials held in a number of Australian universities repositories. Currently around 7,000 cross-disciplinary items are available.
http://search.arrow.edu.au/apps/ArrowUI/


Networked Digital Library of Theses and Dissertations Union Catalog (NDLTD)
NDLTD is an initiative funded by the US Department of Education, which aims to construct a global digital library of electronic theses and dissertations. Most of the participating universities are in the USA, though initiatives from other countries are also included. The collection contains approximately 200k records. 
http://www.ndltd.org/ 

Aeronautical Research Council (ARC) Technical Reports. 
ARC was the principal UK agency investigating aeronautical issues which existed between 1909-1979. The ARC archive is a database of over 3000 historically significant full text reports.
http://aerade.cranfield.ac.uk/reports.html


Caltech Earthquake Engineering Research Laboratory (CEERL) Technical Reports
Approximately 1180 earthquake engineering technical reports. 
http://caltecheerl.library.caltech.edu/


Energy Citations Database
The Energy Citations Database is produced by the US Department of Energy (DOE) Office. It contains bibliographic records for energy and energy-related scientific and technical information from the DOE and its predecessor agencies. It includes citations to report literature, conference papers, journal articles, books, dissertations, and patents. Some of the more recent resources/documents are available in full text.
http://www.osti.gov/energycitations/


Geotechnical, Rock and Water Resources Library (GROW)
The GROW Digital Library is a learning object repository and portal in the area of Civil Engineering which aims to provide free, high-quality digital learning objects that can be used for self-study or repurposed for instructional needs. The repository contains over 1000 approved resources. The service is US based and funded via NSF and other partnerships.
http://www.grow.arizona.edu/

Digital Library Network for Engineering and Technology (DLNET)
DLNET was a project funded by the National Science Digital Library (NSDL) initiative to develop a repository to archive Learning Objects that support pedagogy and learning in Engineering and Technology. As of June 03 the collection comprised of around 1200 learning objects (approx 600 archived at DLNET and 600 Metadata records to object held at other sites). The DLNET project ended in June 2003.
http://www.dlnet.vt.edu/


National Engineering Education Delivery System (NEEDS) 
NEEDS is a US digital library of learning resources for engineering education. NEEDS provides web-based access to a database of learning resources where the user can search for, locate, download, and comment on resources to aid their learning or teaching process.
http://www.needs.org/

JORUM
The JORUM repository is a searchable repository of learning and teaching resources for use by academic and support staff in the UK. The service is due for launch during late 2005 and currently contains over 1500 objects. An Athens username and password are required to access the resources.
http://www.jorum.ac.uk/


PSIgate
PSIgate is a free service that offers access to high quality Web resources in the physical sciences; astronomy, chemistry, earth sciences, materials sciences, physics, and science history and policy.
http://www.psigate.ac.uk/


Aerade
Aerade provides access to key aerospace and defence information sources. A searchable catalogue of more than 28,000 quality Internet resources is provided.
http://aerade.cranfield.ac.uk/



Engineering Subject Center Resource Database
The Higher Education Academy Engineering Subject Centre Resource Database is a searchable catalogue of over 1000 learning and teaching resources for engineering academics. It contains information for lecturers about learning and teaching (e.g. case studies, information about educational theory and practice). 
http://www.engsc.ac.uk/er/resources/index.asp