Association for Computing Machinery

The ACM Digital Library includes full text of computing literature, including some ebook content.

ASCE Digital Library
American Society of Civil Engineers, includes conference proceedings from 2000.

ASME Digital Library  

Mechanical engineering; ASME Press ebooks selected from 1998 to the present. 

CRCnetBASE ITECHnetBASE

This ebook collection contains authoritative resources for the study, design, development, implementation, support, or management of computer-based information systems.

IEEE-Wiley Ebooks Library
Available in the IEEE Xplore digital library and Scholars Portal, 415 e-books span numerous content areas, including Bioengineering, Power & Energy and Communication technologies, etc.


Knovel 
Web-based application integrating technical information with analytical and search tools; science and engineering.

Referex

Premium Referex engineering titles available on the Science Direct platform.

SPIE eBooks

SPIE Press series in optics and photonics: SPIE Press Monographs; Tutorial Texts; Field Guides. 

Synthesis Digital Library 

Engineering and computer science titles published by Morgan and Claypool. Also available on the the Scholars Portal platform -- select "Morgan & Claypool" from the drop down menu.