Possibly nothing illustrates to journey from 4GL to "low code platform" better than Uniface, although there are other survivors from the 20th century that are still effective in the modern world (Magic Software Enterprises Ltd, for example, or Progress).
At Bloor, we think Uniface is doing things right. In particular, that's because Uniface keeps its customers up-to-date with the latest technology, but also allows them to migrate to this at their own pace. Now, with Uniface 10, we think the Uniface Platform is going to be accessible to a much wider community. This latest release is particularly timely because 'low-code,' model-driven development driven by systems architects and business analysts is especially appropriate to the 'Mutable Enterprises' - those enterprises in a constant state of change and reinvention, in response to changes in the business environment - which Bloor sees emerging.
Now, Uniface version 10 has just been released; and what this means is that all the goodies in the re-written Uniface are now available to the whole Uniface community, not just to developers of new projects and web applications.
This is good, because I think that the real differentiator for a low-code platform is soon going to be its developer community, which is a lot bigger (and, dare I say it, sometimes more innovative) than its vendor's own developer group - Open Source communities are the model. Looking at it from a different point of view, if the vendor and the community collaborate well, developers buying into a low-code platform with a large and active developer, and 3rd-party software vendor, community are less at risk from any decisions made by the vendor and the impact of "lock-in" is reduced. I believe that Uniface has plans to develop its existing developer community further, with the help of a free (for non-production deployment) community edition of Uniface 10, and I hope these come to fruition sooner rather than later.
I have heard it suggested that low-code platforms such as Uniface, with a demonstrated ability to cope with the "heavy lifting" needed to automate a whole enterprise, are no longer as relevant as they once were. This might be because organisations are mostly fully automated already, or buying enterprise software off-the-shelf, and all they need is a lightweight, agile, platform for orchestrating existing services. There is certainly more scope for lightweight orchestration these days but there is still a risk that, as you come to depend on such tools, you reach levels of complexity or scale which are beyond their capabilities. At which point, business agility can be impacted severely.
It is always good (that is, lower risk), all else being equal, to work in an environment that doesn't have a "cliff edge" you can fall over as you scale up or things get more complex. It's really a matter of an organisation's enterprise architects managing - being in control of - its technology architecture, and many organisations will want the sort of confidence something really capable of "heavy lifting", like Uniface, can provide.