Together with Pyramid Technology and Sequent Computer Systems, Alliant's machines pioneered the symmetric multiprocessing market.

Alliant was founded, as Dataflow Systems, in May 1982 by Ron Gruner, Craig Mundie and Rich McAndrew[1] to produce machines for scientific and engineering users who needed smaller, less costly machines than offerings from Cray Computer and similar high-end vendors.

The shared system cache and a special concurrency bus implemented low latency concurrency control that could be exploited automatically by high-level language compilers to provide data-parallel processing among the CEs.

Like many early multiprocessing systems, the FX series ran a version of 4.2 BSD Unix on the IPs and CEs, known as Concentrix which initially added multiprocessor support and new VM and IO sub-systems.

Subsequent releases added features such as the first striped Track File System (TFS) and support for real time scheduling (FX/RT).

A second series of FX machines, introduced in early 1988, replaced the CE with pin compatible new custom hardware known as the Advanced Computational Element (ACE).

The ACE, with its higher level of integration using more advanced ASICs, also required less printed circuit board space allowing it to return to the 18x18 inch square profile used by the other system boards in the main chassis.

The i860 was an early superscalar CPU that allowed the programmer access directly into the pipelines; with custom coding the 860 was a very fast system, making it perfect for supercomputer applications.

Alliant's final product series was the CAMPUS/800, a massively parallel machine based on units similar to the FX/2800 known as ClusterNodes and sharing a total of up to 4GB of unified memory.

The largest CAMPUS system created included 192 ClusterNodes in total, and provided 4.7 GFLOPS.