René Hesse
“It was a great time, and I remember it fondly.”
More than twenty years later, an e-mail arrived after René had visited this museum. It did something source code cannot do: it put a human voice back into the archive.
Software remembers what it did. People remember what it meant.
ACARSd survives in source trees, binaries, screenshots, databases and recovered network data. But projects like this were also built from trust, experiments, arguments, late-night conversations and people teaching themselves things because the project suddenly needed them.
This section preserves those recollections. René Hesse's message is the first contribution.
“A lot of memories came back.”
René's reply began simply: he was pleased to hear from KjM again and said that browsing the new museum brought back many memories. He remembered the ACARSd years as a good time — and his mail quickly filled in details that had almost disappeared from the surviving technical record.
“It was a great time back then, and I remember it fondly.”
Editor's note: quotations on this page are English translations of René Hesse's German e-mail, received in August 2026.
An Airmaster 2000, Windows 3.11 — and DDE
René remembered starting with a hardware Airmaster 2000 decoder from England and WinACARS 1.31, which ran under Windows 3.11. Its only useful interface was Windows DDE. That limitation became an integration problem — and therefore another small ACARSd project.
“I wrote a WinDDE-to-port converter in VB6, and we built the ACARSd port into it.”
The surviving binary is known as acarsds. Its source code was never checked into the ACARSd CVS archive, so René's recollection is especially valuable: it documents why that bridge existed and what it connected.
Learning because the project required it
One of the strongest parts of René's mail was not about an ACARS feature at all. It was about what happened around the software. Working with KjM and the ACARSd servers pushed him into technologies that were new to him at the time.
“Because of you and your servers, I had to deal much more with new subjects such as Linux, MySQL and web programming — Tcl/Tk and PHP, for example. And to this day I still can't program C. ;-)”
He also remembered the communication behind the development:
“I can still remember that we sometimes chatted on Skype for hours.”
That is precisely the kind of history that a CVS tree cannot preserve. A feature may appear as a changed file and a timestamp; the hours of discussion that produced it disappear.
Trust before GitHub permissions
René's most personal observation concerned access. ACARSd was a hobby project, but its infrastructure was real: Linux machines, databases, services and source code. KjM trusted people who had become part of the project even when they had never met face to face.
“Without your trust — even though we never met in person — giving me root access to the Linux systems and the source code, I probably would not have taught myself many of these things.”
That trust had consequences well beyond ACARSd. René still works with aviation data today. He described a modern stack that could hardly look more different from Windows 3.11 and DDE: ADS-B feeders, Raspberry Pi systems, Docker, readsb and tar1090, while his own aviation site now uses Vue.js, Vuetify, PHP and Python.
The story continued: Skyliner
René also recalled inheriting Skyliner Aviation, the project of Chris Witt. Long after the ACARSd years, he migrated its old PHP 5.4 application and shop to PHP 8 using wrapper functions and integrated Skyliner Express with Vue.js and a PDF viewer. It is a small but telling continuation of the same history: knowledge learned around one aviation project migrated into another.
And then there is the FR24 question
René ended one thought with an unavoidable counterfactual. With today's AI-assisted development, he wondered whether the group might even have managed to establish an alternative to Flightradar24.
“With the support of today's AI, perhaps we might even have managed to establish an alternative to FR24 — which today makes good money from it.”
The museum cannot answer that question. ACARSd and ATLAS demonstrate that the technical direction existed: distributed receivers, central collection, aircraft databases and live map visualisation were already part of the work. But history took another route, including the FlightGlobal agreement described elsewhere in this museum. What remains certain is simpler: the project gave people room to learn, build and experiment.
“It was a hobby project — and it was a lot of fun.”
“Thank you for your trust back then.”
Thank you, René — for answering after all these years, for filling in pieces that were missing from the archive, and for being part of the ACARSd story in the first place.
René's route table behind getflight
The recovered server source later supplied another detail to René's story. The original /bin/getflight service was a compiled C CGI program. It first queried the normal flights table and, when no usable route was found, fell back to a special table named fsroute.
KjM remembers that fsroute was maintained specifically by René Hesse. Route information curated by René could therefore become the server-side fallback returned to ACARSd installations around the world.
A storage device makes an unexpected return
Years after the main ACARSd development period, René still hosted private database-heavy services on the INLINE infrastructure. KjM remembers that René supplied a roughly 256 GB SSD to reduce that database load.
In 2026 the historical reconstruction produced an accidental full circle: the newly recovered ACARSd database — tens of millions of records reconstructed from surviving binary uploads — is being built on that same SSD.
Source note: the fsroute fallback is preserved in the recovered getflight source; René's maintenance of that table and the SSD history are KjM's 2026 recollections.
Add your voice
If you used ACARSd, ran a server, tested a build, supplied data or simply remember those years, the museum would like to preserve your side of the story too.
Nothing will be published automatically. Contributions can be edited or withheld from publication on request.