Crossplatform random number generator

Got following code from Wiki: http://en.wikipedia.org/wiki/Random_number_generation

m_w = <choose-initializer>;    /* must not be zero */
m_z = <choose-initializer>;    /* must not be zero */

uint get_random()
{
    m_z = 36969 * (m_z & 65535) + (m_z >> 16);
    m_w = 18000 * (m_w & 65535) + (m_w >> 16);
    return (m_z << 16) + m_w;  /* 32-bit result */
}

This should be what you need: http://en.wikipedia.org/wiki/Linear_congruential_generator

If you need a truly portable implementation, the best option would probably be to just use a custom random number generator, such as this Mersenne Twister implementation or Colin Green's Fast Random Number Generator. By controlling the implementation, you can guarantee that you'll get the same results given the same seed on any platform.

There's also the Troschuetz.Random library available through NuGet which provides several "standard" randomization methods which are presumably available on other platforms as well:

Fully managed library providing various random number generators and distributions. More precisely, this library offers 7 generators (ALF, MT19937, Standard, XorShift128, NR3, NR3Q1, NR3Q2), 6 discrete distributions (Bernoulli, Binomial, Categorical, DiscreteUniform, Geometric, Poisson) and 21 continuous distributions (like Normal, Exponential, ChiSquare, Beta, and so on); moreover, it offers a random class similar to the one Python offers (TRandom).

All the hard work behind this library was done by Stefan Troschütz and optimized within this .NET package by Alessio Parma.