In December 2017, the Advisory Committee for DOE's Office of Advanced Scientific Computing Research (ASCR) was asked to document some of the major impacts of ASCR and its predecessor organizations. This seemingly simple request kicked off a multi-year process of information gathering, distilling, curating, and refining. Input was provided by over 100 scientists.

ASCR's prehistory can be traced back to John von Neumann's advocacy for a mathematics and computing activity in the years following the Manhattan Project. Through many twists and turns, ASCR played a pivotal role in creating the entire discipline of computational science through investments in basic research, leadership-class facilities and computers, workforce development programs and much more.

This full history is described in the document ASCR@40: Highlights and Impacts of ASCR's Programs. Although it is impossible to cover everything in a 100-page document, to our knowledge, this is the most comprehensive history ever written on the topic. We expect it to be useful to scientists, students, and historians of science.

A more expository introduction to this subject can be found in ASCR@40: Four Decades of Department of Energy Leadership in Advanced Scientific Computer Research. This is a less technical document with a series of short articles that convey many  highlights of ASCR's activities. We expect this to be of interest to a broader, perhaps less technical audience.

A more terse description of key ASCR advances and capabilities can be found in ASCR@40: Topical One Pagers. This is a collection of 11 one-page synopses of key ASCR impacts in a consistent and easy-to-digest format. We expect these materials to be useful to educate busy decision makers, or perhaps to whet the appetite for deeper dives into the other two documents.