The Terragen milieu that began as long ago as the rise of the Sephirotics and continues to thrive and grow in the present day is in some ways unique, and unlike anything that existed in the pre-Nanoswarm days of Old Earth or even in the Interplanetary Era. Though there is huge diversity, and there are exceptions to every rule, there are a few factors which affect nearly all Terragen cultures:
1) Depth of history: With the exception of deletions due to the Nanoswarms or possible memetic manipulations by the transapients, human and other Terragen knowledge back to 4000 b.c.e. or more is accessible. This gives an unprecedented perspective of 16,000 years. Great thinkers of the past retain an effect, especially if they were the first to explore a new field, in which case they may still be remembered by name. This is particularly true of those who were active in the formative years of Terragen culture on Old Earth. Similarly, some religions are still active and even popular after many millennia of life. Others may be extinct or submerged but have a continuing memetic effect through descendant religions or through general cultural effects. Likewise, some of the great art and literature of the past has not lost its appeal and status in all the time since, but has been recopied, translated, and imitated in new forms down through the ages. Even works which seem to have left public consciousness, and have apparently vanished from the collective subconscious are still accessible through old records, and may be revived, sometimes after millennia of obscurity. The availability of good records and expert translation programs has greatly eased individual access to a culture of unprecedented memetic richness.
2) The Wormhole Nexus: Travel, trade, and even mass migrations over the Wormhole Nexus act to homogenize cultures which are in contact with it, just as the transportation networks of the Industrial Age and later times, by moving people and populations.
3) The Known Net: The rapid spread of information across the Known Net acts to homogenize cultures by meme propagation, a situation that finds it origins as far back as the data networks of the Information Age. Fashions and ideas, especially those with multi-clade appeal, have been known to sweep across whole sets of societies, affecting many trillions of sapient beings within a matter of only a few months or years.
4) Light Speed Limitations: Outside the existing networks, cultures commonly evolve undisturbed for years, decades, or even centuries. This is a strong force for diversity, through cultural drift, founder effects, etc., even for cultures which are in contact with the Beamrider Network. Unlike pre-singularity civilization, which in the end created a single inclusive culture that destroyed or strongly modified all others on the planet of Old Earth, the culture of the civilized regions in modern times is not a pervasive and all-powerful solvent. Diversity and novelty persist, at least until the arrival of links to the Known Net, and Wormhole Nexus. Many of the strongest and most vibrant local cultures survive even this impact, and may remain more or less intact and unique for millennia.
5) Inter-Clade Diversity: Unlike different human cultural groups, clades do not usually assimilate one another through blending and intermarriage. This produces persistent diversity. Memes can cross gaps between clades, though their progress across clade boundaries can be uneven (see Intraclade Biases). Individuals certainly can, but rarely do. Though there is a constant trickle of individuals who are willing to undergo substrate conversion for one reason or another, this is a small fraction of the total population. For one clade to assimilate (or for the two together to form a new hybrid clade) another through physical blending and reproduction is even more extraordinarily rare. This is a source of creative tension, and also a persistent source of division and dispute, especially where two or several clades belong to the same polity. The common trend in Terragen history has been that new clades are produced at a much higher rate than old clades disappear.
6) Intraclade Biases: Sapient bionts are predisposed by biology towards some memes, and resistant to others, and therefore tend to produce cultures within a certain range. Each terragen clade has a different set of "natural" biases, and in consequence a different natural range of cultures. The other clades are direct descendants, or were provolved or programmed by humans, so there are some similarities both deliberate and accidental, but also some significant differences. Xenosapients provide another and truly alien set of biases in their interaction with the overall meme pool.
7) Technological Stability: The rate of change from the point of view of SI<1 entities is much slower than it was during the pre-nanoswarm (Industrial Age through to Space Age) periods, though not so slow as it was during the Palaeolithic. Cultural patterns have had time to "settle" so that they match the tech chosen by a clade. Customs suited to a particular technology, an a particular time and region have sometimes been well rooted for millennia, and are nearly invisible to their inhabitants.
8) Political Stability: Some AIcracies have remained in place, essentially unchanged, for thousands of years, like Egyptian society in the Age of Agriculture. Other AI "gods" have encouraged unprecedented stability in the lesser polities of sapient being who are under their direction.
9) Prosperity: Definitions of wealth and poverty shifted drastically with the rise of the Sephirotics and the nanotopia post-scarcity economy; energy and materials are available to all, food (or the equivalent) is rarely scarce, and sophisticated manufactured goods are commonplace. In terms of absolute resources available to them, even the least citizens of nanotopias are incomparably wealthier than the wealthiest pre-Singularity rulers and elite.
10) Extreme Longevity: Many S<1 individuals live for 1000 years or more until some accident destroys them, since aging is greatly reduced even for bionts or vecs. Even when they do die, they may be succeeded by "backups" who are from the point of view of the backups and many of eir associates the same individual. This is apt to greatly reduce the rate of cultural change. Attitudes towards final physical death may be extremely relaxed (many have "seen it all" in this life) or conversely some will greatly fear it since they still have their relative youth and health.
11) Archailect Rule: Humanity (to give the example of the original biont sophont species of Old Earth) is once again demoted to a secondary role and is no longer "in the driver's seat"; the relative attitude of independence found between the Renaissance and the end of the Information Age is usually seen as an anomaly. Propitiation of "gods" and "spirits" or, for the skeptic, forces which are intelligent but uncontrollable (the Archailects) is once again the norm. Even anti-AI movements exist in opposition to this memetic. A return to "magical" thinking is often found. Human and other terragen impulses to worship may or may not attach to the Archailects themselves, but the presence of the Archailects affects every religion and philosophy, even those which pre-date or actively oppose the influence of transapients.
12) Toposophic Stratification: Between the Archailects and the lower grades of sophonts are many intermediate beings. Some are fully sophont and independent; others are subsystems of the archailects. Some of these intermediates (lower and higher transapients, and lower archailects) have evolved and ascended from the human condition, whereas others were "created" full fledged at their native toposophic level. Every level of transapient existence constitutes an entire kingdom of being, and state of galactic civilization and existence. While many have no interest in lower sophonts, others are concerned about sapient welfare, and some again (mostly beyond the boundaries of the civilized galaxy) simply exploit or enslave sentients of singularities lower than their own. Unlike the society of Old Earth, galactic civilization is stratified and multilayered. Some have compared this situation to pre-Industrial Age feudalism, or to the pre-scientific belief in hierarchies of angels, or "the great chain of being" in Old Earth terragen thought. Others find such metaphors imprecise or misleading.
13) Virtual Realities: For Virches their virtual environment may be "the" reality, and they may know and wish to know no other. In many cases, though, citizens of such bottle-worlds yearn to know what the real universe is like, either out of intellectual curiosity or from an urge for continued survival (since the computronium which supports virtual life must still be maintained in the actual universe). While some may be content to observe the actual universe through sensors and translators, others actually seek to experience life in the non-virtual universe, and embody themselves. The influence of these few seekers on embodied communities may be considerable, not only because of their radically new viewpoints (a common effect of any sort of interclade immigration) but because of their understandable skepticism concerning the ultimate nature of reality itself. In the other direction, many vecs, bionts, and cyborgs spend large portions of their life in virch surroundings either for business or for pleasure, just as many humans in the Information Age apparently spent a large fraction of their time in front of a computer if they had one available.
14) Mass Society: Nearly every existing clade maintains societies with interconnected numbers of people that would have boggled the mind of any Palaeolithic human, who might not have been aware of more than a few dozen or a few hundred other sapient beings. The pattern of larger and denser communities began during the Age of Agriculture, and continues unabated in mainstream societies of the Terragen milieu today. Isolationist persons and cultures exist, but they are the minority.
Asymptote System - Text by Anders Sandberg A place where many species converge. Usually trading and network nexuses, and generally core systems for a Cooperative Venture. As time goes by, many species end up in asymptotes when their outside branches die out, go static or transcend. Asymptotes can often be quite dynamic civilizations with vital internal politics, but most long-lived asymptotes have developed stabilizing systems that keep them viable even when the constituent species die out, merge or transform.
Environment - Text by M. Alan Kazlev  The physical or virtual surroundings in which sentient beings live; The air, water, organisms, minerals, and other external objects that surround and affect an organism.  From the perspective of any system, rest of the world or universe.  Any precious biosphere, especially a garden world.
Eugenics - Text by Tony Jones Some transapients attempt to shape species using selective breeding.
Extinction Event - Text by M. Alan Kazlev Extinction of a lesser or greater number of biological or alife species, usually as a result of environmental trauma, deliberate extermination or assimilation (e.g. by a blight or swarm) or inability to compete with rival organisms.
Fads and Fashions - Text by M. Alan Kazlev Every society knows its fads and fashions; since the dawn of mass communications during the late Industrial Age, such fashions have influenced many millions of persons at a time, and in a few cases today such fashions spread to suitable societies via the wormhole network to blanket the entire Terragen Sphere.
Industrialization - Text by Stephen Inniss, after the original by M. Alan Kazlev The development of a manufacturing sector in a region's socioeconomy. The actual effects of industrialization vary dramatically according to the level and the type of the technologies employed and according to the local culture's prior experience with managing those technologies.
Novelty Node - Text by Stephen Inniss In memetics, a region or time of particular memetic influence, one that generates new concepts, philosophies and fashions that influence a broad region and may have effects lasting for decades, centuries, or even millennia. A number of such nodes have been or are presently active within the Terragen sphere. Some of these are associated with full-blown Renaissance Events.
Paranoid, Paranoids - Text by M. Alan Kazlev Generic term for individuals, subcultures, or communities who have adopted the meme that the SI:1 and higher intelligences wish to coldly dominate, manipulate, and/or exterminate S<1 sophonts, and that salvation lies through establishing hider communities, through high level cryptography, or through setting up communities or civilizations beyond the reach of of the archai.
Polity - Text by M. Alan Kazlev An organized society; a state or quasistate; any form of politico-social organization.
Pop Culture - Text by Anders Sandberg and M. Alan Kazlev The accretion of fads and fluff that has built up over the millennia - ever changing in details, ever constant in fundamentals. Although most pop-culture is S<1, there is also a rich tradition of transingularity pop-culture.
Renaissance Event - Text by Stephen Inniss A flowering of artistic creativity, scientific discovery, technology and trade, together with some significant changes in the operation of personal culture, and a political ferment. There is typically a "rediscovery" of some older cultural models and information or an influx of new foreign ideas, or both, and usually an upsurge in local population. A renaissance event often sets the pattern for future cultural development in ages to follow.
Translation and Language Cladization - Text by Anders Sandberg Instead of unity and a single tongue, there was a great cladization of languages during the first federation era. This is because the different habitats got together and could hardly understand each other, and AI was now so cheap that everybody could afford translator devices. So instead of forcing linguistic convergence (although some did their best to make a fedspeak), a lot of clades diverged further protected from outside influences in cocoons of translation.
Translation Metamorphosis - Text by Tony Jones A problem which can arise when virch entities move from one virch environment to another is that there are beings which will be so altered by the translation that they are effectively utterly different beings in the two different virches.