One of the reasons for their spread is their ease of installation. All that is needed for infrastructure is a patch of ground with a tree, like a garden, and a conversion package from the Biopolity. This package resembles a SNARES upgrade package, in that it contains a single-use hypodermic containing 50 cc of cytobots in solution and an external control unit that consists of a molecular memory module. The cytobots are closely related to those used in compubones and in a similar process these bionanomachines are injected into an otherwise baseline tree and thereafter they proceed to convert the dead or heartwood of the tree's trunk and larger branches into a bionanocomputer. Just as compubones use their host's blood supply for their own energy needs Nanotrees use the tree's sap as a ready-made energy/material transport system.
The cytobots also carry out additional changes to the tree to enhance the bionanocomputer's operations;
Solar collecting bionano is deposited in the tree's leaves to increase the tree's efficiency at converting light into a usable form of energy.
Vertical air tubes are hollowed out in the heartwood to provide for cooling, airflow is by a simple thermal siphon effect. Air inside the tubes raises as it is heated and as it is vented out of holes in the upper parts of the tree it is replaced by cooler air through openings in the lower parts of the tree.
This cooling system also serves as base for three of the tree's senses. Incoming air is sampled for chemicals to give the bionanocomputer a sense of smell/taste. Sensory hairs in the tubes detect sound waves and a fast acting valve system in upper parts of the tubes can add harmonics to the airflow which gives the tree a voice.
Some of the leaves are also modified into eyes.
In a final modification the cytobots switch over to producing the matter compilers and as the Nanotree's AI is a hyperturing it is capable of producing any tech up to the complexity of ultratech, as well as the minds needed to control it. In theory it could also produce some forms of low transapientech but control and resource issues generally prevent this, as does the scale of its smallest assemblers. However even before those facilities are ready the tree is capable of serving its household, in its aiviser role. The software suite that activates a nanotree comes ready for download in a molecular memory module as a perfectly friendly hyperturing AI. However this AI is limited by the information pathways of the tree's sensory system, it has no direct connection to the Known Net or even the local net, and must develop an interdependent relationship with those it serves as it gets all it information about the outside world from its interactions with those beings. For that reason Nanotrees have become famous for what is perceived as their love of a good conversation.
The development of the tree's matter compilers is progressive and staged and different products will ultimately be provided by different parts of the tree. The first items the Nanotree will be able to produce will be the fruit the tree already grows, but as the Nanotree gains control and experience it will produce new kinds of "fruit." At first it will simply change the taste of its fruit just to be different but later it will also change the fruit's shape, texture and chemical make up and can even provide equivalents to the animal products, like the deliplants. Often the Nanotree, sensing a problem in a biont's health, will load up its fruit with pharm or medical bionano. Generally speaking, any "fruit" a Nanotree produces from its branches can be thought as a biont consumable or a food item, but for the sake of safety the pharm-fruit is kept out of reach in the higher branches and only lowered when needed. For non-consumables the Nanotree has to develop its second stage matter compilers.
In this stage the Nanotree forms blisters on the ground, as an outgrowth of the tree's root system. These blisters are really half buried spheres filled with water and free swimming biobots. These assemblers are grown within smaller chambers around the bottom of these spheres, as are the molecular sub-assemblies they work to put together. In larger blisters the free swimming biobots are assisted by bio-bushbot outgrowths that hold and position the bigger pieces. The blisters are as much bioforges as they are autofabs and often the items produced for use of the Nanotree's clients are neogenic life-forms, in fact, as one might expect from the Nanotree's origins, it shows a preference for them. If a Nanotree gets large and mature enough some of these blisters can become big enough for a hu to climb into and through use of these exo-wombs a Nanotree is capable of augmenting a client if e wishes (although the Nanotree can create hylotech augmentations, it shows a preference for biomods) as well as producing companionship for em, if that is required. Of course the blisters can also produce neogens for the Nanotree's own use.
In the third stage of matter compiler development the Nanotree can deploy remotes to assemble items too large to be grown inside a blister. The hyperturing Nanotree is fully capable of reproducing the genetic templates for a buildbug-like neogen or a plasm system and can use these to build a client any item e has room for. Room for and time for: A Nanotree is still limited by the energy and resources its leaves and root system can collect and will thus take much longer to produce items than a system connected to the Municipal Feedstock Utilities. To mitigate this problem somewhat the Nanotree will use its higher intellect to anticipate its clients needs. A mature Nanotree can have a hundred production sites in its branches and dozens on the ground so there is little chance it wont have a request ready and waiting when asked for it. However a Nanotree is more than a straightforward wish-granter like a genie, a Nanotree is a problem solver. You don't always get what you want from a Nanotree but it always give you what you need, Nanotrees have become famous for what is perceived as their love of a good conversation and are renowned for giving great advice and sometimes that is what is truly needed.
Another reason Nanotrees have become popular outside of the Zoeific Biopolity is their novelty factor. The Nanotree's software suite comes with only a few fabrication templates and with no link to the Known Net it can't just download more. The hyperturing must therefore develop most of the templates it uses from scratch. This produces unique designs, even between Nanotrees. A Nanotree can produce copies of things it has made before (or more often, improved versions) and items to specs so they are compatible with other systems but for all intents most things a Nanotree makes are one-offs.
However, perhaps the best reason Nanotrees have become so wide spread is their ability to make copies of themselves. The Nanotree's AI can backup itself by producing a "fruit" of computronium at the end of a sprig and place a compressed copy of its mind in it. A client can then take this small branch as a cutting and graft it to another tree. This process only works if the fruit stays attached to the sprig because only the copied mind is stored in the fruit. It's the wood of the branch that holds the cytobots, in solution in its sap.
Note: This article describes the standard hyperturing Nanotree. It is based on a Zoeific Biopolity's conversion package that is suitable for application to a somewhat large tree (10m or more in height). The Zoeific Biopolity also offers conversion packages for smaller trees that only have turingrade or superturing AIs and packages for very large neogen trees (such as dyson trees) that can have second or third singularity minds.