C :

#include<stdio.h>
int main(){
int i,j,k;
  for(i=0;i<4;i++){
    for(j=3;j>i;j--)
      printf(" ");
    for(k=0;k<1+2*i;k++)
      printf("*");
    printf("\n");
  }
  for(i=0;i<3;i++){
    for(j=3;j>=3-i;j--)
      printf(" ");
    for(k=0;k<5-2*i;k++)
      printf("*");
  printf("\n");
  }
  return 0;
}

C++ :

#include <stdio.h>
#include <math.h>
int main() {
	int i, j;
	for (i = 1;i <= 4;i++) {
		for (j = 1;j <= 4 - i;j++)
			printf(" ");
		for (j = 1;j <= i + i - 1;j++)
			printf("*");
		printf("\n");
	}
	for (i = 3;i >= 1;i--) {
		for (j = 1;j <= 4 - i;j++)
			printf(" ");
		for (j = 1;j <= i + i - 1;j++)
			printf("*");
		printf("\n");
	}
	return 0;
}

Pascal :

begin
  writeln('   *');
  writeln('  ***');
  writeln(' *****');
  writeln('*******');
  writeln(' *****');
  writeln('  ***');
  writeln('   *');
end.

Java :

public class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
    int kongge=3,xinghao=1;
    for( int i=0;i<4;i++,xinghao=xinghao+2,kongge-- )
    {
    	int kongge2= kongge ,xinghao2 = xinghao;
    	while( kongge2-- >0 )
    	{
    		System.out.print(" ");
    	}
    	while(xinghao2-- > 0)
    	{
    		System.out.printf("*");
    	}
    	System.out.println();
    }
    kongge= 1;
    xinghao=5;
    
    for(int i=0;i<3;i++,kongge++,xinghao=xinghao-2)
    {
    	int kongge2= kongge,xinghao2 = xinghao;
    	while( kongge2-- >0 )
    	{
    		System.out.printf(" ");
    	}
    	while( xinghao2-- >0 )
    	{
    		System.out.printf("*");
    	}
    	System.out.println();
    }
		
	}

}

Python :

print("   *")
print("  ***")
print(" *****")
print("*******")
print(" *****")
print("  ***")
print("   *")