PDF Font Tester
This online application for testing fonts will allow creating your own layout, position and colour text strings and generate a PDF file. The resulting PDF is not vector based but is rasterised to 300dpi CMYK image so fonts can't be used for commercial printing. The application allows using OpenType features.
PDF Font Tester is very easy to implement, after uploading he fonts, it is a matter of adding a single line of code <iframe> to the client's website. Client has partial control over the appearance of the tester and which OpenType features are offered for testing.
Annual licence costs €300 for up to 10 font families (or 60 single fonts), €450 for up to 20 font families (or 120 single fonts); €550 for up to 35 font families (or 210 single fonts); €650 for up to 50 font families (or 300 single fonts); €750 for up to 100 font families (or 600 single fonts).
If you need higher flexibility in implementation, there is also a possibility to use API implementation, allowing full control over the appearance of the tester, access of multiple font instances and manual control of all paramaters. You will have to design your own user interface before the implementation. There is an additional costs for using API method.