Holodeck B2B

Overview

Holodeck B2B is open-source software for standards-based business messaging, built around ebXML Messaging 3 and AS4. It is best suited to teams building an AS4 gateway or adding messaging to a business system, rather than organizations seeking a general-purpose invoicing app. Its standards focus and integration options are strengths, but deployment requires a separate Java runtime and may call for backend work beyond the included file integration.

Key features

It can operate as a standalone AS4 gateway or connect to a business system through provided interfaces. One-way and two-way exchange, using either push or pull patterns, makes it suitable for workflows that need to send and receive messages. Files and attachments can reach 2 GB, a useful ceiling for larger exchanges.

Gateway monitoring is available through both command-line and graphical interfaces, so operations teams can choose a text-based or visual approach. File-based backend integration is included. REST API integration is an extension, while teams can build custom Web Services or JMS backends using the API. This gives organizations room to fit the gateway to existing systems, but REST or custom integrations add work beyond the included file path.

Security features include message signing and encryption using WS-Security 1.1.1, certificate trust stores, OCSP checks, and AS4 non-repudiation of receipt. The maker describes the software as AS4 compliant and identifies compliance with e-SENS/CEF eDelivery, ENTSOG/ENTSOE, EESSI, and Superstream profiles. An open-source AS2 extension allows one gateway to handle both AS2 and AS4, with the protocol selected in the P-Mode.

Pricing

Holodeck B2B is free: the Holodeck B2B plan costs nothing and is open-source software under GNU GPL 3. There is no free trial because there is no paid plan to trial. The free plan makes it possible to use the software without a subscription charge, but the binary package does not include Java; deployment requires JRE version 11 or later.

Version 7.0 is released under GNU GPL 3. The maker says LGPL3-licensed interfaces are included for connecting to closed-source systems through those interfaces. Organizations needing help directly from the developers can purchase a support contract.

Platforms

Holodeck B2B supports Linux, macOS, and Windows. Whichever platform is chosen, teams must provide Java 11 or later separately.

Who it's for

This is a focused choice for organizations that need AS4 messaging as part of an eDelivery solution, especially where compliance with one of its named profiles matters. It is also a fit for teams that can operate a gateway and use file-based integration, an extension, or the API to connect business systems. Organizations looking for a ready-made invoicing workflow rather than messaging infrastructure should consider an electronic invoicing product instead.

Pros and cons

• Pros: Standards-based AS4 messaging, two-way exchange, and support for attachments up to 2 GB suit substantial B2B document flows.
• Pros: Monitoring through both command-line and graphical interfaces offers operational flexibility.
• Pros: An included file backend, REST extension, and API for custom backends provide several integration paths.
• Cons: Java 11 or later must be supplied separately, adding a runtime requirement to deployment.
• Cons: REST is an extension, and custom backends must be built, so teams needing those paths should account for integration effort.
• Cons: Its scope is B2B messaging infrastructure, not a complete electronic invoicing application.

Alternatives

For an invoicing-focused shortlist, see Electronic Invoicing Software. Consider Billit for a freemium Peppol invoicing option with a free plan for sales invoices and limited functionality; its free plan includes Peppol e-invoicing, while the paid plan shown costs €690 per mont.

B2Brouter is another freemium option, with a free Basic plan limited to 10 contacts, 24 transactions per year, and one user; choose it if those limits suit your invoicing needs. BillingEngine may suit users looking for a small-scale invoicing plan: its free tier allows three invoices, three quotes, and three receipts per month for one user.

ONESOURCE Pagero is a freemium alternative with a free-access plan. PeppolSoft offers a free Buyer plan with receiving, a web portal, and an app. Tungsten e-Invoice Connect has a free plan capped at 25 invoices per month, with higher-volume plans for 100, 500, and more invoices per month.

Unimaze is a paid alternative. Vertex e-Invoicing is also paid and requires contacting Vertex for pricing; country and jurisdiction coverage varies, and VAT compliance periodic reporting is an add-on.

Verdict

Choose Holodeck B2B if your organization needs a free, open-source AS4 gateway with defined security capabilities, profile compliance, and options for connecting it to business systems. Its strongest reason to choose it is the combination of standards-based messaging and adaptable integration paths; look elsewhere if you need a turnkey invoicing application or want to avoid managing a separate Java runtime and integration work.