At Fruit Tree Labs, we specialize in dialogue systems — enabling natural language conversations between users and machines. Our focus is on supporting makers to create engaging dialogue-driven interaction as part of their products. We believe that regardless of whether the product is supposed to bring joy (like a video game), or has a more serious goal (like health coaching) - the interactions with your end-users should always be simple, engaging and fun!

Dialogue is how people interact with each other everyday, and sometimes it can be an intuitive way to interact with a technology. As experts on the topic, Fruit Tree Labs can advice you on how to improve your user's experience through dialogue-driven interaction (or whether it's perhaps not a good idea to do so).

We don't just advice though — we have our own software platform that can be used to implement dialogue-driven interaction in web, mobile, or desktop apps: DialogueBranch. And the best part is that it's completely free and open source.

The History of Fruit Tree Labs

Fruit Tree Labs is a start-up company that is born out of the European Research and Development environment, consisting of interdisciplinary collaborative projects between Academia, Industry and SMEs.

In 2016, with our friends and colleagues from Roessingh Research and Development and the University of Twente in the Netherlands, we successfully proposed a EU Horizon 2020 project called "Council of Coaches", which would later prove to be the starting point for Fruit Tree Labs and our open-source dialogue platform: DialogueBranch.

Council of Coaches would build a virtual group of health advisors that could debate among themselves, and with the user, in order to provide balanced lifestyle advice. The 1996 video game Sid Meier's Civilization II included a "Council of Advisors", who would provide different viewpoints on what the player should focus on in successfully managing their civilizations. Council of Coaches raised the question: can we apply that concept to a more serious use case? And the answer was yes...

Image showing the transformation from the Civilization 2 High Council to the Council of Coaches demonstrator. Image: From "High Council" to "Council of Coaches".

Council of Coaches was one of 7 projects out of 187 submitted proposals that was granted funding in the H2020-PM-15 call. The project received around €4 million in R&D funding, and ran between September 2017 and 2020 (3 years). The project generated three main outcomes:

  • A proof of concept showing that vicarious persuasion and a council of health advisors is indeed a viable approach to health and lifestyle coaching (Hurmuz et al., 2022).
  • A highly innovative platform for the creation of 3D embodied conversational agent applications, integrating various tools developed by the University of Twente, Sorbonne University, and the University of Dundee, published under the "Agents United" initiative.
  • And finally, a branching dialogue platform that was purposely built to power the proof-of-concept demonstrator shown above (see

During Council of Coaches we investigated existing solutions that could support our requirements for implementing branching dialogue that could be authored by domain experts. We really wanted to have full control over the dialogues we presented to our users, instead of moving to dialogue generation tools. Some of the solutions that appeared on our radar were Twine, Dialogue Designer, and Yarn. Yarn appeared to be the most promising, although being aimed at game developers, had some features that we considered too complex. Combined with the fact that Yarn wasn't nearly as popular, well-documented and well-supported as it is today, we decided to build our own language, parser and tools. Thus, the first iteration of DialogueBranch was born.

The dialogue platform that was first created during Council of Coaches (2017-2020) has survived the "R&D Valley of Death" and has seen multiple further applications after the end of the project.

After the end of Council of Coaches, the EU H2020 Project "SmartWork", the EU AAL Project "Leaves", and a Dutch national research project "PACO" were the first three digital health use cases that used the dialogue platform to power a conversational agent component. From 2021 to 2023, the platform has seen steady growth, further supported by and used in EU Horizon 2020 projects "RE-SAMPLE", and "iHelp".

Even though the dialogue platform has seen growth, both in uptake and in development, the platform has never been the primary focus of any of its contributors. With the founding of Fruit Tree Labs, that has changed, as we are fully committed to the uptake and development of the new DialogueBranch platform.

Fruit Tree Labs Target Industries

So, at Fruit Tree Labs we know a thing or two about dialogue-driven interaction... but who might benefit from this? In this second blog post we explore who would be the main possible beneficiaries of our dialogue platform and expertise...

The Research & Development Community

Innovators that want to push the boundaries of technology, and bring positive societal change through new technologies often use collaborative, public-funded R&D projects as a starting point. In these projects, one needs to build strong consortia, with diverse knowledge and background to tackle the innovation challenges. Fruit Tree Labs is the perfect partner in any consortium that aims to build innovations that could benefit from dialogue-driven interaction.

Why are we a good partner? For one, we are hyper-focused on dialogue-driven interaction, while being domain-agnostic. Whoever your intended target users are, our dialogue platform could be a technology-fit. Second, we have over 15 years of experience in participating in highly innovative R&D consortia — we can participate, coordinate and help shape competitive proposals. And finally, our dialogue platform is completely free and open-source, covered by an MIT License — this means that there is zero barrier to further exploitation beyond the life of the project. From our side, there will be no tedious IP- and exploitation agreement discussions. Ever.

The list of European research projects that have used the dialogue platform to power a dialogue-driven interaction component includes: SmartWork, LEAVES, iHelp, RE-SAMPLE, and of course the project that started it all: Council of Coaches.

Image showing the project logo's for Council of Coaches, iHelp, Leaves, SmartWork and RE-SAMPLE Image: European research projects that have used our dialogue platform to Power their dialogue-driven interaction component.

Commercial Apps in Behaviour Change and Related Domains

There is still a large (and growing!) wish-list of features for our dialogue platform — the work is far from done. However, the foundation is solid, and our platform is being used in commercial applications even today.

Fruit Tree Labs can assist commercial applications that want to integrate dialogue-driven interaction into their products today, using our own dialogue platform: DialogueBranch. From our point of view, the type of applications that would benefit most from DialogueBranch are those that require in-depth interaction with their users, such as eLearning, interactive guides, and "behaviour change" applications. Especially in contexts where the correctness of the information provided is of paramount importance.

Designing an effective behaviour change application is extremely challenging. This has been our bread-and-butter for the past decade. See for example our work on tailoring physical activity coaching systems (op den Akker et al., 2014), or our framework for generating motivational message (op den Akker et al., 2015). Needless to say, we have experienced the challenges of behaviour change first-hand. Ultimately, an effective behaviour change application builds up a relationship with the user, is able to educate, convince, motivate, and nudge users towards good behaviour. Dialogue-driven interaction through an (embodied) virtual agent is an ideal way of tackling all of this, because it allows for very personalized and in-depth coaching.

Read more about our dialogue platform at to see if it is the right fit for your application — or contact us to see how we can help, advise or integrate into your platform.

(Computer) Role Playing Games

And finally... video games! DialogueBranch and the way we design dialogue-driven interaction is extremely inspired by the classic CRPGs of old: Planescape Torment, the Baldur's Gate and Icewind Dale series, as well as the games that sparked the CRPG revival like Pillars of Eternity, Divinity: Original Sin and the Pathfinder CRPGs. We love video games, and we would love to make our contribution to the field.

Even though we are not making video games ourselves, and we're not part of "the gaming industry", we are very open for collaborations in this domain. So if you are making games — and if you're looking for a partner, we would love to get in touch.