We believe the title says it all, feel free to ask for more details if you please.
Dr. Khamphousone
Cardinal Optimizer, a.k.a., COPT, is a high end commercial optimization solver from a company headquartered in China, although with extensive operations in Europe and elsewhere. Its four founding developers have PhD's from Stanford University (whose spots teams are known as "the Cardinal"). It has done very well on Mittelmann benchmarks.
It currently has LP, convex QP, convex MIQP, convex (MI)QCP, MISOCP, and Linear (convex) SDP capabilities. There is also an exponential cone capability in development. It has many interfaces.
More info at COPT Github, Cardinal Optimizer (COPT) main German location site, and Cardinal Operations main site (in China)