Hellbore beam used during the Schism War against Tyler, a Timeloopist world; the beam is almost invisible until it hits atmosphere
An advanced plasma weapon firing a bolt of monopole contained plasma at near fusion temperatures. An adaptive high energy laser guides the bolt through atmospheres, and via an advanced application of the ponderamotive effect, compresses the monopole contained bolt to a critical density at the desired range. At critical density, monopole-catalyzed fusion occurs, resulting in rapid release of the mass-energy in the plasma. In atmosphere, primary energy release is thermonuclear-equivalent shock wave and heat release, with a secondary laser impact. In vacuum, energy release is soft x-rays, with secondary laser impact. Some versions add trace amounts of elements in the plasma or monopoles to generate specific effects (e.g. neutron or EMP production), similar to older style so-called "enhanced nuclear weapons".
Smart Weapons - Text by M. Alan Kazlev, from Anders Sandberg's Big Ideas Grand Vision Weapons with have varying amounts of intelligence in them (rarely more than turingrade). The simplest Smart Weapons link to a control-command subturing and give the owner the ability to shift between types of ammo, see through the aimpoint camera etc. This kind of connection is necessary for use in teamware, and is practically standard among even the simplest baselines. The scramjet bullets of the sabot pistols of Trillicon have built in cameras and some limited steering capabilities. Zetatech's Marksman Gun is equipped with a n expert system that can act as a point defence or drone if placed on a tripod or suitable vehicle (although the price tag deters most people).