Trolanport is a capital city of canals and commerce. While Sharn may be the largest city in the continent, Trolanport nearly matches it for the sheer volume of economic activity. Not only have the gnomes set up a favorable port for goods from all over - Seren relics, Xen'drik treasures, Riedran fineries - but many dragonmarked houses have major enclaves, as Trolanport is the center for the elemental binding trade.
Dragonmarked Houses
The fundamental tension in Trolanport is between the four dominant gnome clans (the Clebdechers, the Lonadars, the Tarliachs, and the Trolans) and the dragonmarked houses. Each of the clans represents a diverse portfolio of economic interests, while the houses are specialized based on their mark. Furthermore, the clans utilize a complicated system of sharing ownership of businesses to split profits and decisionmaking via the trading of "stocks", a byzantine pile of paperwork that's unintelligible to outsiders.
While the houses have monopolized their industries elsewhere in Khorvaire, they have failed to extend that dominance to Trolanport. Some of this is due to natural gnomish ingenuinity making up for the supernatural skills of dragonmarked members. More importantly is the gnomish talent for subterfuge presenting a challenge unlike anything else the houses have faced.
The Docks
While canals and small ships fill the city, the key to Trolanport's rise was its docks. The Trolan clan are renowned shipbuilders and founded the city centuries ago, still maintaining a majority stake in the city's shipping business. They have cordial relationships with both the Clebdecher and Tarliach clans, who provide essential materials for their ships. The Clebdechers have a dominant stake in the city's livestock, textiles, and alchemy businesses. The Tarliachs control the farming and logging that goes on around the city, bringing the raw materials to be worked into ships.
Sailors visiting Trolanport know the gnomes do not tolerate the reckless brawling of Sharn's Cliffside district. Still, the gnomes freely encourage drunkenness and the indulgence of other vices as a way to acquire information and potential blackmail. The Trust is behind every front of organized crime on the docks, carefully entrapping shady figures and protecting the citizens of the city.
The hottest business at the docks now is Sarlonan art. The leading socialites of Trolanport have declared that Tashana shifter art is "in", much to the chagrin of the Riedran traders who are now "out". The Inspired Lords of Riedra see their Tashana Tundra neighbors to the north as uncivilized at best, and cannot fathom why the refined gnomes would showcase such "savage" art during the weekly galas.
For their part, the gnomes delight in learning about foreign cultures and treat them with great respect. The great competition now is to get actual shifters from the Tundra to a gala and interact with them, but so far the gnomes have run into trouble making this happen. Many suspect Riedran interference, and are considering interfering back if their desires are still frustrated.
Elemental Binding
Elemental Binding is a complicated process with results that define modern Khorvaire. The mighty lightning rail and airships attract plenty of attention, but smaller elemental-bound items are just beginning to enter the market.
Binding an elemental into an item is a complicated process. First, khyber shards of appropriate quality must be acquired. Second, an alchemical treatment must be applied to the shard to enhance it's "carrying capacity" and to enable the power of the bound spirit to be harnessed. Third, the shard must be enchanted with proper conduits for its power. Fourth, the shard must be installed in an appropriate item, which requires a different set of arcane principles in the construction of the item. Finally, the power of an item may require siberys shards tuned to an appropriate dragonmark to be commercially viable.
Of these five steps, the Dragonmarked Houses are only included in the last two. The Lonadar clan has the strongest ties to the mountain clans that own Khyber shards for the first step, who then sell them to the Clebdecher clan for the second alchemical step. The Lonadar clan then buys the alchemically-treated shards and enchants them. Cannith does the majority of the work for the fourth step, but Lonadar artificers still consult on new item designs. The fifth step is the only one entirely under the control of the houses, where Cannith and the appropriate and relevant house work together to attune the Siberys shards.
The dragonmarked houses have attempted to bypass the Zil's bottleneck on elemental binding, but the gnomes have thus far kept their secrets. Ironically, while the gnomes claim their ingenuity led to the key abjuration and alchemical breakthroughs responsible for modern elemental binding, the truth is the gnomes themselves stole the abjuration rituals from the Sulatar drow of Xen'drik. To be fair, the gnomes in conjunction with the houses have dramatically improved upon Sulatar techniques, but the fundamental breakthrough was pirated from the Sulatar. Those who know this secret history fear that one day, the Sulatar will have revenge.