11 months is young. My ped said that the averages for motor skills have been changed in the past 10 years. When we were babies, it was typical for little ones to start walking around 1 year, but now that has been changed to closer to 15 months. Since they are now supposed to sleep on their backs, many babies just don't spend enough time on their bellies to develop the muscle strength for motor skills until a bit later than they did years ago. Plus there is a wide range of development - you may see other babies standing/walking at his age, but others are just not as active. The different areas of development grow at different rates and in different orders for some children. Children that are very communicative may be slower to develop motor skills. It all evens out and doesn't mean they will be delayed in any way. It's just like adults - they have different interests and different strengths. The other thing I've read is that development can be inherited. If you and your son's father were later walkers, then he might be as well. It's no guarentee though.
Give your little guy lots of time to play on the floor. Create obstacles like pillows to climb over and tunnels to scoot through. Put toys up on low stable tables/sofas that will encourage him to work to get them. Get down with him and crawl around. All of those things will help him to be happy and have fun without realizing that he's gaining strength and skills. Before you know it, he'll be reaching up to new levels and will be up on his feet. There is research that walkers/stationary play centers are really not that helpful for developing the necessary muscles for walking. It is the same for jumpers. All of them hold babies' hips/legs in a way that is different than what they need to do to walk. Using them occasionally won't cause them harm, but it's really best for them to have more time being free to explore on the floor where his legs and hips can be free to have full rotation and movement.
It doesn't sound like there is any reason to be concerned about his development. It's always exciting when they move on to the next step, but remember that you can never go back and those steps pass so quickly. Try to enjoy where he is now and know that soon enough he'll be toddling around and bumping his little head into everything in the house and will be covered in plenty of bruises.