MakeHuman is a software that, as I understand, began as a module for Blender. However, it's been available as a stand-alone application for some time. The software is basically a small application that lets you customize a human character, that you can then export to different formats depending on your needs.
Using MakeHuman feels similar to Poser. You have different tabs for different categories, and you also have “dials” on the side, to modify the body shape and facial features. On the first tab, you can change the basic parameters, body height, muscle mass, weight, and you can also use 3 race sliders (African, Asian, Caucasian) to change the look of the character. There is also a gender slider that lets you go from male to female, and vice versa, depending on the gender of your character.
Then, you can go into more details. For example, you can change the shape of your character's breasts (if you are creating a woman), torso size, waist size, arms and legs shape, etc. A nice feature is being able to use symmetry.
You can modify one side of your character, and then use a button to apply those modifications to the other side. This is specially useful since, unlike Poser or Daz Studio, the dials in MakeHuman don't have numbers, so you can't simply copy values from one side to the other (you can only set the sliders as close as possible to each other).
MakeHuman also lets you apply skin materials to your character, and also includes extra geometry items, like clothing, hair, lashes, and teeth.
There's also a tab where you can add a rig to the character. However, something that I found really nice is being able to add a facial rig that you can use to animate the face in your target application.
When you are done, you can save your model and also export the model to different formats. You can export to Collada, FBX, OBJ, Ogre and others. Export will also include the rig in those formats that support it. Additionally, this will also save the facial rig.
MakeHuman is a simple but very useful tool if you create human characters that are used in any project. It's easy to understand and use, but it can provide really good results. On top of that, it's free.
Get MakeHuman: http://www.makehumancommunity.org/