For me the main advantages of Bibble are its portability between different operating systems (it's the best RAW developer for Linux) and its extensibility by third party plugins, which will help you to perform typical photo-editing tasks without the need to open other editors like Photoshop or Gimp.
This page contains a good collection of plugins developed by others for Bibble.
Harry
Harry is a black and white converter filter using a color equalizer. The grayscale intensity can be adjusted for each of seven basic colors individually.
Harry offers the most flexible and customizable black&white conversion: it can be used to enhance the contrast of the image, to separate gray values of different colors, and to accentuate a color in the black&white image.
Note: The conversion function is optimized to avoid the appearance of the noise in the processed image. However noise can appear if extreme settings are used (adjacent sliders with big differences). In this case a strong color noise reduction and/or Noise Ninja filter will help, but the best solution is simply to avoid these settings.
Harry is available for Bibble 4 (freeware) and Bibble 5 (pay as you want).
Harry can be downloaded from the Download page.
Example images
Sally
Sally is a selective color filter which allows adjusting the parameters like the luminosity, hue, saturation, and vibrance of seven basic colors.
Sally is useful to correct or fine-tune a color, enhance parts of the image like the sky, vegetation or the skin tones. Sally offers total control over all the parameters of each color.
Using an intuitive interface you can select the parameter to adjust from the tabs in the interface, than adjust the selected parameter individually for each color from the list.
Note: Like Harry, the Sally plugin may cause noisy results with extreme settings. These artifacts can be avoided using a color noise reduction and/or the Noise Ninja filter.
Sally is available for Bibble 4 (freeware) and Bibble 5 (pay as you want).
Sally can be downloaded from the Download page.
Example images
SallyPro
SallyPro is the ultimate color processing plugin for Bibble. It manipulates every parameter of the colors based on every possible criterion.
The colors can be adjusted based on their hue (7 colors) and luminosity (midtones, highlights and shadows). The controls can be grouped to alter all the luminosity or all the hue range in a quick and simple way. The parameters controlled by SallyPro are the luminosity, hue, saturation and vibrance.
Another feature of SallyPro is the possibility to quickly preview the affected areas on the photo for each slider. This helps to quickly identify the colors which need to be altered for the desired effect.
SallyPro has a double interface, so you can choose your preferred configuration of the controls. You can even use both interfaces in parallel for an even more intuitive way to use SallyPro: modifying a value on an interface will update the other interface automatically.
SallyPro is available for Bibble 4 and Bibble 5. Because the limitations of the Bibble 5 Previews, some features are still missing from the Bibble 5 version: the buttons aren't implemented.
The Trial version of SallyPro can be downloaded here, the full version can be purchased here.
Lay
It changes the alpha channel of any layer based on a color selection. It gives the user even more control and flexibility on the layers.
Probably the greatest advantage of Lay is the possibility to use any tool on a color selection, not only the color parameters, as Sally does : for example sharpening, noise reduction, curves, other plugins, etc...
As Lay works differently than the usual plugins, you should read this tutorial explaining how this plugin works.
Note: Lay can be only used on user created layers, not on the main layer
The demo version of Lay is fully functional, the registered version has a more intuitive interface and the possibility to preview the transparency of the layer for greater control. The unregistered (demo) version cannot be used for commercial purposes.
The demo version of Lay can be downloaded here, the full version can be purchased here, pay as you want. Don't forget to check out the Lay tutorial.
iNDA
It contains 20 typed of different films, 5 color filters, a basic gamma and a saturation control.
iNDA is based on Serge Minkovski's great B/W Film Simulation plugin for GIMP and Petteri Sulonen's work.
iNDA is released under the GNU General Public Licence.
iNDA can be downloaded from the Download page.