
You can produce some very striking plots with LabPlot. (Thanks to Alex for this and the other images)
Some years back, I wrote about a
collaboration between KDE’s LabPlot and the Qt-based SciDAVis projects. Together, they were working on the next generation of free plotting software and were engaging in a backend overhaul before presenting results in a new user interface.
A few weeks back, Alexander Semke, one of the lead developers of LabPlot, got in touch to tell me that they would soon be reaching a beta release of LabPlot 2. While there is still work to be done, this should be a big step on the route towards an up to date version of LabPlot that will be usable to scientists from day to day. Of course, I downloaded the source and decided to give (what will become) LabPlot 2 a go.

LabPlot 2 currently enables creation of attractive plots, includin LaTeX equations.
LabPlot uses a project metaphor that enables the user to work with multiple spreadsheets of data and plots of those data, experimenting or producing slightly different views of the same data.
Conveniently, if you already have your data in a form ready for plotting, you can specify the file source directly from LabPlot and skip opening the data as a spreadsheet (very useful if the data source is large as processing it into a spreadsheet can be slow at present). Plots created directly from an external file in this way will get automatically updated if the external file changes. So, if you have run a simulation and got some results, you can plot them directly in LabPlot, spot an error or something to change, re-run your external simulation and have the plot within LabPlot update automatically for the new data. Related to this feature, it is possible to save only a link to the external data file within your LabPlot project, rather than all the data, saving lots of space for large datasets.

You can arrange windows conveniently in tabbed interface.
It is also possible to generate your data from within LabPlot by creating a new spreadsheet and entering values – useful if you want to quickly visualise a few data points. In this way, you could also easily remove known bad data points from within LabPlot itself.
LabPlot can produce various x-y plots at present with all the normal features you would expect (plot colours, legends, axis adjustments and labelling). It can also incorporate LaTeX equations, convenient for anyone already familiar with the typesetting language. Plots can be exported to PDF, EPS, SVG or PNG formats, offering a range of high-quality options. You can, of course, stack multiple plots in the horizontal or vertical directions too.

Plots can be stacked vertically or horizontally within one image.
Spreadsheets and plots can be arranged as separate sub-windows within the LabPlot main window or as tabs within the interface, making it easy to keep track of different datasets and plots.
LabPlot 2 is still in its pre-release phase and has some stability issues – it is not uncommon to come across a crash during use. However, the new interface is working and it is possible to produce good quality plots quickly and easily. The project shows a lot of promise and now would be an excellent time to join the effort.
The LabPlot team is looking for coders, of course, but also needs help in many other areas. Simply testing out the pre-releases and submitting bug reports will be very helpful. The developers need to know in which directions to concentrate development. What should be the priorities? Fast reading of real-time data? Add more features for editing 2D-plots? Add scripting capabilities? Add data analisis features like fitting, signal processing? LabPlot is free software. That means, whether a coder or not, you can help to shape its development and ensure that it matches your needs, now and in the future.