ZeeZide / Freelance:
Working on projects/products for ZeeZide GmbH,
as well as doing freelance work in the
If you got some interesting project, feel free to contact me. Meanwhile, have fun with our demo projects: CodeCows and ASCII Cows!
Technologies: CalDAV, CardDAV, Noze.io, Swift, etc
Helped a tech startup to implement a roaming solution,
primarily working on the iOS SDK and the iOS application parts.
Server side Swift running on the client, yay!
Technologies: Noze.io, Swift, UIKit
I worked on building a
MAPI message store provider
which stores Outlook entities into
capable WebDAV servers.
Well, ZideOne has ceased operations. Don't ask.
Technologies: C, C++, SQLite, MAPI, GroupDAV, WebDAV, CalDAV
Chamber Management System:
I design and lead the development of a web based management system
for a chamber of pharmacists in Germany. The system is built
in Java on top of OpenGroupware.org technology.
Timeframe: Nov 2007-Jul 2009
Technologies: OGo, Go, OpenOffice.org, Java
SKYRIX Software AG
I architect, implement and maintain extensions to the OGo groupware
This includes work across all layers of OGo, from the application
logic through protocol layers up to the web interface.
Technologies: C, Objective-C, Linux, PostgreSQL, SOPE
An enterprise scale SMS/MMS transaction and service platform which is
in use by various large media customers, MNOs and SMEs.
My primary work is on system reliability, mobile handset detection and
on-the-fly MMS repurposing.
Timeframe: Feb 2006-Sep 2007
Technologies: MMS, SMIL, C, Objective-C, Java, Tomcat, Linux, PostgreSQL
To secure the data in a large scale deployment of electronic
we configured a
warm standby replication cluster using the write ahead logging
facility of the server.
The datarooms are accessed using a set of
Ruby on Rails
Timeframe: Apr-Aug 2007
Technologies: PostgreSQL, Ruby on Rails
Card Management System:
For a large German trust center I architect and lead the development of
a system to securely manage applications for qualified signature /
encryption cards (health professional cards).
Prototypes implemented in SOPE, later moved to Java/Go.
Timeframe: Feb 2004-Apr 2007
Technologies: Java, Jetty, Go, SOPE, HPC, Smartcards, OpenSSL, MySQL
For a large French ministry I designed and led the development of a
massively scalable groupware server. Designed to serve 60.000 ministry
The project kicked off the ScalableOGo OpenSource project which is currently
being continued by Inverse.
Technologies: C, Objective-C, PostgreSQL, GroupDAV, WebDAV, CalDAV
Designed and implemented an administration web interface for various
Linux services. A proprietary OGo component which is in use in the
Technologies: OGo, Objective-C, Linux, SOPE
Enhanced the SKYRIX web application server (now OGo) with an enterprise
content management system. Was in use at a large plant research institute
to maintain thousands of documents in a structured way.
Technologies: OGo, Objective-C, SOPE, Content Management
OpenSource / Sparetime
Internet Relay Chat (IRC)
protocol implementation for
a basis for building your own IRC servers, clients and bots,
a sample IRC server
(including a web client),
as well as
some IRC bots,
written in the
Technologies: Swift NIO, IRC, Swift, WebSockets
protocol implementation for
Redis client library
and a fast Redis server written in Swift:
Technologies: Swift NIO, Redis, Swift
A tiny but useful Express-like web framework built upon
the new async-IO Swift framework by Apple.
Popular blogpost in which we build µExpress:
A µTutorial on Swift NIO.
Technologies: Swift NIO, Swift
Swift Package Manager
directly within in Xcode.
Ready-to-go Xcode templates for
iOS apps, macOS tools, SwiftNIO and Kitura.
No more swift package generate-xcodeproj!
Technologies: Xcode, Swift Package Manager
Custom SQL functions and types for the PostgreSQL database server,
written in the Swift programming language.
That is what PL/Swift does.
Technologies: PostgreSQL Extensions, Swift
Write code that works on both, UIKit and AppKit.
Not only useful for deployment to macOS, but during development,
reduce simulator/device testing annoyances.
Technologies: UXKit, AppKit, Swift
Swift Server Project HTTP APIs:
GCD based, asynchronous implementation
of the proposed, official Swift Server API.
Maybe this gets pulled, maybe not. Probably not :-)
Technologies: GCD, Swift
Host Swift within Apache, that is, reliably :-)
Stay tuned, a preview is available, but something bigger is in the works.
Technologies: Swift, Apache, mod_dbd
Want to edit Vue components in Xcode, but they just show up in black&white? Trying to change the file type using the 'Type' popup, but Xcode can't remember? Use VueXcode.
Technologies: Swift, Vue.js AppKit, Xcode, Cocoa
Standalone Swift ORM / database access library primarily inspired by EOF,
and in consequence CoreData, adding some ActiveRecord concepts.
Can be used on Swift server, mobile or desktop.
Technologies: Swift, EOF, CoreData, SQLite3, PostgreSQL, mod_dbd
for the Swift programming language
that work on ARM platforms, specifically the
Including Server Side Swift via
Technologies: Swift, Docker, RaspberryPi
A toolkit to write native Apache modules in Swift.
Includes a subset of the Connect/Express framework of
which makes it very easy to write modules.
Instead of reinventing the HTTP server, hook into something that just works
and is battle proven.
Technologies: Swift, Apache, JSON, HTTP
The "Server Side Swift aS a Service" toolkit ;-)
Noze.io are Node.js-like, evented I/O streams for Swift.
Implements core Node modules like leftpad, net or http,
as well as some external ones, like Connect and Express.
Technologies: Swift, GCD, JSON, HTTP, Streaming
SwiftSockets is kind of a demo on how to integrate Swift
with raw C APIs.
More for stealing Swift coding ideas than for actually
using the code in a real world project.
It also comes with a great Echo daemon as a demo, it's
always there if you need a chat.
Technologies: Swift, GCD, Expat, XML, HTTP
Go is a set of Java frameworks to build powerful Ajax, web and web service
applications. Comes with a lot of WebObjects compatibility as well as
support for Zope concepts.
Timeframe: 2005-2010, 2014-today
Technologies: Java, Tomcat, Jetty, Eclipse, JDBC, HTML, WebObjects, Zope
A groupware server designed for massive scalability. The result of the
Agenor project. This is a completely stateless application with a novel
storage concept which allows high scalability despite using a RDBMS
storage backend. For 60.000+ users.
Technologies: GroupDAV, PostgreSQL, SOPE, Objective-C
we designed a new groupware protocol to allow the lots of OpenSource
groupware servers to connect to OpenSource groupware clients.
Timeframe: Dec 2004-2009
Technologies: WebDAV, iCalendar, vCard, Calendaring
I'm the project lead of
and coordinate the small but excellent community. Doing talks on
Currently working on the Java port of OGo, OGo/J.
Technologies: C, Objective-C, Linux, PostgreSQL, SOPE
Initially a clone of the WebObjects 4.5.1 web application framework,
SOPE was enhanced with concepts from the modern Zope environment.
SOPE is the application server used by OGo as well as SOGo.
Includes a large collection of modules:
XML parsers, iCalendar/vCard processing, NIO streams, EOControl,
MIME/IMAP4 support, LDAP wrappers, database drivers, the appserver
Technologies: Objective-C, HTML, WebObjects, Zope, Database C Libraries, MIME, IMAP4, LDAP, EOF, XML-RPC, SOAP, SAX, DOM
A clone of the OpenStep Foundation library, similar to gnustep-base.
Initially developed by Ovidiu Predescu and friends. Took over maintenance
around 2000. Worked on adding support for garbage collection.
Technologies: GCC, Objective-C, Boehm-GC
Worked on various GNUstep subprojects. Improved the gnustep-make library,
assisted the creation of the GSWeb framework, enhanced the GNUstep database
library with additional adaptors and features. Bugfixes in the base library.
Technologies: GCC, Objective-C, Make
Designed and assisted implementation of garbage collection support for
GNU Objective-C in cooperation with Ovidiu.
Technologies: C, ObjC Runtime, GCC
Implemented an Objective-C wrapper around the GNOME gtk+ GUI library.
Modelled after AppKit where possible, integrated NSRunLoop with the X11/GDK
Technologies: C, gtk+, X-Windows
An Apache module to enhance the server with regular Objective-C
Technologies: Apache API, C, ObjC runtime
Wrote an Objective-C / Python bridge for use in the Skyrix 3 web application
server. Full support for Java-Bridge like 'jobs' files and a Pythonic API
Technologies: CPython Embedding, ObjC runtime
Skyrix 4 server. Allowed users to write small applications using HTML and
Technologies: C, ObjC Runtime, Mozilla SpiderMonkey
A non-streaming Apache module to forward HTTP requests to backend application
servers. Capable to distribute requests across cluster nodes with a central
registry daemon (snsd). Support for sessions stored in volatile memory.
Now part of SOPE.
Technologies: C, Apache 1/2 API
Small AppKit application to view OOo files. Loads the XML stored in
the OOo file, transforms it into HTML which is then displayed in a
Technologies: AppKit, WebKit, OpenDocument Format, XSLT, Objective-C