70-m dish of Evpatoria Deep Space Center in Ukraine to six star systems resembling that of the Sun on August 29 and September 3 and 4, 2001. The message consists of three parts: Section 1 represents a coherent-sounding radio signal with slow Doppler wavelength tuning to imitate transmission from the Sun's center. This signal was transmitted in order to help extraterrestrials detect the TAM and diagnose the radio propagation effect of the interstellar medium. Section 2 is analog information representing musical melodies performed on the theremin. This electric musical instrument produces a quasi-monochromatic signal, which is easily detectable across interstellar distances. There were seven musical compositions in the First Theremin Concert for Aliens. The 14-minute analog transmission of the theremin concert would take almost 50 hours by digital means; see The First Musical Interstellar Radio Message. Section 3 represents a well-known Arecibo-like binary digital information: the logotype of the TAM, bilingual Russian and English greeting to aliens, and image glossary. Star systems to which the message was sent are the following: Cosmic Call 2 (Cosmic Call 2003) message The Cosmic Call-2 message contained text, images, video, music, the Dutil/Dumas message, a copy of the 1974 Arecibo message, BIG = Bilingual Image Glossary, the AI program Ella, and the Braastad message. Algorithmic messages Algorithmic communication systems are a relatively new field within CETI. In these systems, which build upon early work on mathematical languages, the sender describes a small set of mathematic and logic symbols that form the basis for a rudimentary programming language that the recipient can run on a virtual machine. Algorithmic communication has a number of advantages over static pictorial and mathematical messages, including: localized communication (the recipient can probe and interact with the programs within a message, without transmitting a reply to the sender and then waiting years for a response), forward error correction (the message might contain algorithms that process data elsewhere in the message), and the ability to embed proxy agents within the message. In principle, a sophisticated program when run on a fast enough computing substrate, may exhibit complex behavior and perhaps, intelligence. CosmicOS CosmicOS, designed by Paul Fitzpatrick at MIT, describes a virtual machine that is derived from lambda calculus. Logic Gate Matrices Logic Gate Matrices (a.k.a. LGM), developed by Brian McConnell, describes a universal virtual machine that is constructed by connecting coordinates in an n-dimensional space via mathematics and logic operations, for