Which countries?
You can still be a developer, of course, and be responsible for critical software projects. You just can't call yourself an engineer.
The license is also seen as largely irrelevant in software as unlike traditional disciplines there are no legislative requirements to have a P.Eng. sign off on certain types of work, nor does most software development fall under the definition of engineering. In contrast, I work in the power industry and the involvement of a P.Eng. is usually a necessity at the design, construction and commissioning phases of utility electrical work.
Also, Canadian jurisdictions do not distinguish between disciplines of engineering in licensing, a Professional Engineer is responsible for self-regulating themselves to the areas of practice in which they are competent. That is, a Professional Engineer holding a degree in mechanical engineering can seal electrical schematics, if she feels that she is competent to do so.
In short, yes you can be a Professional Engineer as a software developer in Canada, but since most software work is not considered to be engineering under the official definition[1], one does not need to be a P.Eng. to do it.
Source: I have an iron ring.