A very low cost multivalue system by UK based Ladybridge Systems. QM has integrated technologies such as object oriented programming, exception handling and support for arbitrarily multi-dimensional data into the familiar multivalue environment.
The correct name of the product is OpenQM but everyone abbreviates it to QM in general reference. There is a misbelief that the name QM refers to the commercial product and OpenQM to the open source version. The Open in OpenQM simply refers to the fact that there is an open source version available for developers who want to experiment with ideas for possible inclusion in the commercial product..
QM is based on the "Information style" multivalue model, very much like UniVerse, Unidata, etc but has options to select "Pick style" compatibility. The QMClient API gives access to QM from VB, C, Excel VBA, Java, PHP, etc. AccuTerm is bundled with commercial licences.
QM uses a high performance, self-tuning dynamic hashed file system so there is no need for resizing. (Some QM users do not even have a system administrator.) The hashed file system is "binary clean" in that it has no reserved characters and can therefore store binary data such as bit mapped images. There are also "directory files" - much like UV's type 19 - for data exchange with the outside world.
Other key features include support for 32/64 bit environments, IPV6 networking, the Virtual File System for access to external data stores, and Unicode support.
QM has a very low resource usage both in memory and processor power. It is available for all current versions of Windows, most Linux variants, Mac, AIX, Solaris (Intel) and others.
For more information: http://www.openqm.com/