Here are the leading B2B e‑commerce platforms worldwide (short summary, who they’re best for, and key pros/cons). I’ve prioritized platforms used by enterprise and mid‑market sellers as well as the major global B2B marketplaces.

1. Shopify Plus (Plus B2B / Wholesale)

• Best for: fast-growing brands and enterprises that want quick time‑to‑market, a managed SaaS platform and unified B2C + B2B operations.
• Why people choose it: built‑in wholesale/B2B channel, self‑service portals, custom catalogs/pricing, strong app ecosystem and Shopify’s global infrastructure. (Shopify.com)
• Tradeoffs: higher recurring cost for Plus; very complex, custom B2B workflows (deep CPQ, multi‑step procurement) may require apps or custom development.

2. Adobe Commerce (Magento / Adobe Commerce Cloud)

• Best for: large enterprises and manufacturers/distributors that need deep B2B features and heavy customization.
• Why people choose it: native B2B features (company accounts, shared catalogs, negotiable quotes, PO/credit support, requisition lists), extensibility and ability to handle huge catalogs. (business.Adobe.com)
• Tradeoffs: requires experienced developers/ops to run securely and scale; on‑prem or self‑managed SaaS options imply higher implementation and maintenance effort.

3. BigCommerce (Enterprise / B2B Edition)

• Best for: mid‑market to enterprise sellers that want a SaaS platform with strong B2B/omnichannel and headless commerce support.
• Why people choose it: growing enterprise B2B capabilities (catalog/pricing/terms, CPQ enhancements, multi‑storeheadless options) plus built‑in SEO and marketplace integrations. (BigCommerce.com)
• Tradeoffs: like other hosted platforms, very complex customizations sometimes require headless or middleware patterns.

4. Oracle NetSuite SuiteCommerce

• Best for: distributors, wholesalers and manufacturers that want tightly integrated ecommerce + ERP (single source of truth for orders, inventory, finance).
• Why people choose it: native unification of ecommerce with NetSuite ERP/CRM (quotes → orders → invoices, account balances, gated catalogs), strong B2B workflows and one vendor for back‑office systems. (NetSuite.com)
• Tradeoffs: heavier cost and vendor lock‑in; best when you already run NetSuite or need full ERP integration.

5. Major Global B2B Marketplaces — Alibaba.com, Amazon Business, MercadoLibre (Latin America)

• Best for: companies focused on sourcing, global wholesale sales, or rapid channel expansion into specific regions.
• Why people choose them: massive buyer networks, logistics/financing integrations and marketplace demand (Alibaba and Amazon Business are global B2B leaders). Use these when you need immediate access to buyers or suppliers at scale. (home.alibabagroup.com)
• Tradeoffs: lower margin control, platform fees, competition and less branded storefront control vs. a dedicated platform.

6. Sana Commerce, OroCommerce, Intershop (vertical / B2B specialists)

• Best for: manufacturers, distributors and B2B vendors needing ERP‑centric or industry‑specific B2B features.
• Why people choose them: Sana focuses on real‑time ERP integration; OroCommerce is built specifically for B2B marketplaces and complex workflows; Intershop targets large, global B2B merchants with omnichannel needs. (Vendor pages and analyst/industry writeups show these platforms’ focus on B2B workflows and ERP integrations.) (sana-commerce.com)
• Tradeoffs: niche player selection may require specialist partners; check vertical fit and global support footprint.

How to pick the right one (quick checklist)

• Business model & scale: enterprise with heavy ERP needs → Adobe Commerce or NetSuite SuiteCommerce. Fast launch + lower ops burden → Shopify Plus or BigCommerce.
• Technical resources: limited dev/ops → SaaS (Shopify Plus, BigCommerce); in‑house dev team → Adobe/Magento or OroCommerce for deep customization.
• Catalog complexity: thousands of SKUs / many price lists → Adobe Commerce or NetSuite.
• Global/localization & marketplaces: if access to buyers matters, combine your storefront with marketplaces (Alibaba, Amazon Business, regional players).
• Procurement workflows / CPQ needs: require evaluating built‑in CPQ vs third‑party CPQ integrations (some platforms now add CPQ modules or partner integrations).

If you want, I can:

• map 3–4 finalists to your company size, tech stack and budget and recommend the best fit, or
• provide implementation cost & timeline ranges for any platform above.

Sources (high‑level references used above):

• Shopify partner & product pages about Shopify Plus B2B features and partner solutions. (Shopify.com)
• Adobe Commerce (Magento) official B2B feature pages and docs. (business.Adobe.com)
• BigCommerce press & industry reviews on recent B2B enhancements. (BigCommerce.com)
• Alibaba.com corporate and industry coverage showing its scale as a global B2B marketplace. (home.alibabagroup.com)
• Oracle NetSuite SuiteCommerce B2B product pages describing ERP‑unified ecommerce capabilities. (NetSuite.com)

If you’d like, tell me your company size, annual revenue, geographic markets and any existing ERP/CRM — I’ll shortlist 2–3 platforms and give estimated costs and implementation complexity.