I wish to develop a free application but later possibly make a pro version with additional features and sell that for about $20. I would like to know what restrictions the Lesser GPL places on me if my software includes another piece of software licensed under it.
Specifically I'd like to know:
1) If all of my software will need to be licensed under the Lesser GPL or if it will all need to be open source?
2) Does it just mean that the 'library' licensed under it must continue to be licensed under the Lesser GPL in the distribution of my software?