You can also use tiRTFReport (included with the tiOPF framework on SourceForge). It allow you to use any RTF editor (eg: OpenOffice or MS Office) to design your template report. Then let the tiRTFReport engine populate it at runtime. I used this for years, and preferred to use OpenOffice as my template editor and "print preview" (because OpenOffice has a very nice "read-only" mode which looks just like a print preview report would). The tiRTFReport has many built-in functions, and allows you to define more functions using Object Pascal. All the usual reporting functionality is supported like master/details, groups etc. You can also generate reports from TDataset, Lists classes or your own objects from memory. It is very flexible.
Since about a year ago, I switched to a PDF reporting engine developed for fpGUI Toolkit. Good news is, that there is actually very little dependency on fpGUI. It should take a couple of minutes work to extract any fpGUI dependencies. I'm actually thinking of doing this so it could maybe be consider for inclusion in FPC's FCL. The PDF reporting engine is just that, an "engine that generates PDF's". It doesn't have any visual designers, but the amount of PDF features it has makes up for it. Coding reports with Object Pascal is pretty easy anyway.