{{implementation|BASIC}}'''UBASIC''' is a freeware BASIC interpreter written by Yuji Kida at Rikkyo University in Japan, specialized for mathematical computing.
More information and links can be found at its [[wp:UBASIC|Wikipedia article]].

==Sample Program==
This simple program approximates specific derivatives:

    10  Point 6 'Sets decimal display to 28 places (0+.1^27)
    20  rf=#pi/180 'Degree -> Radian Conversion
    30 Dc=20
   100 Q=73*rf:?Chr(2):?"   F'(Q): Approximation","     Actual Value":N=1:GoSub 1000:?Using(,Dc),cos(Q):N=2:GoSub 1000:?Using(,Dc),1/Q:N=3:GoSub 1000:?Using(,Dc),#pi*Q^(#pi-1)
   999 End
  1000  '*** Print Sub ***
  1010 ?Using(,Dc),.Fp(Q);"  ";:Return
 59999  End
 60000  '*** Function Assignment ***
 60100 .F(N,Q):If N=1 Then Return(sin(Q)) 'Fp=cos(Q)
 60102         If N=2 Then Return(log(Q)) 'Fp=1/Q
 60104         If N=3 Then Return(Q^#pi) 'Fp=pi*Q^(pi-1)
 60105 ?"Invalid Function Code:  N must be '1' or '2' or '3'"
 60109  End
 60210 .Fp(Q):dQ=#eps^0.3:Return((.F(N,Q+0.5*dQ)-.F(N,Q-0.5*dQ))/dQ)
 '' ''
'''''Run'''''ning as written gives:

 Run
  0.29237170472273672804   0.29237170472273672810
  0.78487369196003179303   0.78487369196003179283
  5.27771467407719816786   5.27771467407719816637
 OK