Nonlinear Optimization

Hi,

I have been brought back to the "R-Side" from MatLab. I have used R in
graduate econometrics but only for statistics and regression (linear and
nonlinear). But now I need to run general nonlinear optimization. 

I know about the add-in quadprog but my problem is not QP. My problem is a
general nonlinear (obj funct) with linear constraints.I know about the "ms"
and "nls" functions, but these seem only for nonlinear regression, not
nonlinear minimization. I am looking for a pure non-linear optimization
module.

The nonlinear optimization functions I used in MatLab are "fmincon" and
"fminunc"

Is there any nonlinear optimization algorithm for R?


Thanks.


Rob