diff --git a/src/frontend/help/readhelp.c b/src/frontend/help/readhelp.c
index e9f7dbdc5..ea7a262e0 100644
--- a/src/frontend/help/readhelp.c
+++ b/src/frontend/help/readhelp.c
@@ -62,7 +62,7 @@ hlp_read(fplace *place)
     wordlist *wl, *end = NULL;
     int i, fchanges;
     char *s;
-    bool mof;
+    bool mof = FALSE;
 
     if (!place)
 	return 0;
diff --git a/src/frontend/plotting/clip.c b/src/frontend/plotting/clip.c
index d7da33f89..6e90e6106 100644
--- a/src/frontend/plotting/clip.c
+++ b/src/frontend/plotting/clip.c
@@ -48,7 +48,8 @@ clip_line(int *pX1, int *pY1, int *pX2, int *pY2, int l, int b, int r, int t)
     int y1 = *pY1;
     int x2 = *pX2;
     int y2 = *pY2;
-    int x,y,c,c1,c2;
+    int x = 0, y = 0;
+    int c,c1,c2;
 
     CODE(x1,y1,c1)
     CODE(x2,y2,c2)
diff --git a/src/frontend/plotting/graf.c b/src/frontend/plotting/graf.c
index 5258a889e..2513d2779 100644
--- a/src/frontend/plotting/graf.c
+++ b/src/frontend/plotting/graf.c
@@ -23,7 +23,7 @@ Author: 1988 Jeffrey M. Hsu
 #include "ftedev.h"
 #include <terminal.h>
 #include <variable.h>
-
+#include "../terminal.h"
 #include "graf.h"
 
 
diff --git a/src/frontend/plotting/grid.c b/src/frontend/plotting/grid.c
index c25517bf4..eaf9aa7ec 100644
--- a/src/frontend/plotting/grid.c
+++ b/src/frontend/plotting/grid.c
@@ -229,7 +229,7 @@ lingrid(GRAPH *graph, double lo, double hi, double delta, int type, Axis axis)
     int mag, mag2, mag3;
     double hmt, lmt, dst;
     int nsp;
-    double tenpowmag, tenpowmag2, step, spacing;
+    double tenpowmag = 0.0, tenpowmag2, step, spacing;
     bool onedec = FALSE;
     int margin;
     int max;
@@ -1111,7 +1111,7 @@ drawsmithgrid(GRAPH *graph)
 {
     double mx, my, tenpowmag, d, dphi[CMAX], minrad, maxrad, rnorm[CMAX];
     double pixperunit;
-    int mag, i, j, k;
+    int mag, i = 0, j = 0, k;
     double ir[CMAX], rr[CMAX], ki[CMAX], kr[CMAX], ks[CMAX];
     int xoff, yoff, zheight;
     int basemag, plen;
@@ -1405,7 +1405,7 @@ static double
 cliparc(double cx, double cy, double rad, double start, double end, int iclipx, int iclipy, int icliprad, int flag)
 {
     double clipx, clipy, cliprad;
-    double sclip, eclip;
+    double sclip = 0.0, eclip = 0.0;
     double x, y, tx, ty, dist;
     double alpha, theta, phi, a1, a2, d, l;
     bool in;
diff --git a/src/frontend/plotting/plotcurv.c b/src/frontend/plotting/plotcurv.c
index c50b2a5a2..0883f8c0a 100644
--- a/src/frontend/plotting/plotcurv.c
+++ b/src/frontend/plotting/plotcurv.c
@@ -33,8 +33,8 @@ ft_graf(struct dvec *v, struct dvec *xs, bool nostart)
     register int i, j, l;
     double *scratch, *result, *gridbuf, *mm;
     register double *xdata, *ydata;
-    bool rot, increasing;
-    double dx, dy, lx = 0, ly = 0;
+    bool rot, increasing = FALSE;
+    double dx = 0.0, dy = 0.0, lx = 0.0, ly = 0.0;
     int	dir;
 
     /* if already started, use saved degree */
diff --git a/src/frontend/plotting/x11.c b/src/frontend/plotting/x11.c
index 87b21d985..95613e3ed 100644
--- a/src/frontend/plotting/x11.c
+++ b/src/frontend/plotting/x11.c
@@ -369,13 +369,13 @@ X11_NewViewport(GRAPH *graph)
 						   viewargs,
 						   XtNumber(viewargs));
 	XtAddEventHandler(DEVDEP(graph).view, ButtonPressMask, FALSE,
-			  handlebuttonev, graph);
+			  (XtEventHandler) handlebuttonev, graph);
 	XtAddEventHandler(DEVDEP(graph).view, KeyPressMask, FALSE,
-			  handlekeypressed, graph);
+			 (XtEventHandler) handlekeypressed, graph);
 	XtAddEventHandler(DEVDEP(graph).view, StructureNotifyMask, FALSE,
-			  resize, graph);
+			 (XtEventHandler) resize, graph);
 	XtAddEventHandler(DEVDEP(graph).view, ExposureMask, FALSE,
-	        redraw, graph);
+	        (XtEventHandler) redraw, graph);
 
 	/* set up button box */
 	XtSetArg(bboxargs[1], XtNfromHoriz, DEVDEP(graph).view);
@@ -388,14 +388,14 @@ X11_NewViewport(GRAPH *graph)
 	DEVDEP(graph).buttons[0] = XtCreateManagedWidget("quit",
 	    commandWidgetClass, DEVDEP(graph).buttonbox,
 	    buttonargs, 1);
-	XtAddCallback(DEVDEP(graph).buttons[0], XtNcallback, killwin, graph);
+	XtAddCallback(DEVDEP(graph).buttons[0], XtNcallback, (XtCallbackProc) killwin, graph);
 
 	XtSetArg(buttonargs[0], XtNlabel, "hardcopy");
 	XtSetArg(bboxargs[1], XtNfromVert, DEVDEP(graph).buttons[0]);
 	DEVDEP(graph).buttons[1] = XtCreateManagedWidget("hardcopy",
 	    commandWidgetClass, DEVDEP(graph).buttonbox,
 	    buttonargs, 1);
-	XtAddCallback(DEVDEP(graph).buttons[1], XtNcallback, hardcopy, graph);
+	XtAddCallback(DEVDEP(graph).buttons[1], XtNcallback, (XtCallbackProc) hardcopy, graph);
 
 	/* set up fonts */
 	if (!cp_getvar("font", VT_STRING, fontname)) {
diff --git a/src/frontend/variable.c b/src/frontend/variable.c
index 3304e9f57..e6f476be0 100644
--- a/src/frontend/variable.c
+++ b/src/frontend/variable.c
@@ -455,7 +455,7 @@ cp_remvar(char *varname)
 /* Determine the value of a variable.  Fail if the variable is unset,
  * and if the type doesn't match, try and make it work...  */
 bool
-cp_getvar(char *name, int type, char *retval)
+cp_getvar(char *name, int type, void *retval)
 {
     struct variable *v;
 
diff --git a/src/frontend/variable.h b/src/frontend/variable.h
index 98706bda2..161d6b90e 100644
--- a/src/frontend/variable.h
+++ b/src/frontend/variable.h
@@ -48,7 +48,7 @@ wordlist * cp_varwl(struct variable *var);
 void cp_vset(char *varname, char type, char *value);
 struct variable * cp_setparse(wordlist *wl);
 void cp_remvar(char *varname);
-bool cp_getvar(char *name, int type, char *retval);
+bool cp_getvar(char *name, int type, void *retval);
 wordlist * cp_variablesubst(wordlist *wlist);
 wordlist * vareval(char *string);
 void cp_vprint(void);
diff --git a/src/include/cpextern.h b/src/include/cpextern.h
index 8d676b257..daac18a79 100644
--- a/src/include/cpextern.h
+++ b/src/include/cpextern.h
@@ -167,7 +167,7 @@ extern void cp_vprint(void);
 extern void com_set(wordlist *wl);
 extern void com_unset(wordlist *wl);
 extern void com_shift(wordlist *wl);
-extern bool cp_getvar(char *name, int type, char *retval);
+extern bool cp_getvar(char *name, int type, void *retval);
 
 /* cpinterface.c etc -- stuff CP needs from FTE */
 
diff --git a/src/maths/ni/nipzmeth.c b/src/maths/ni/nipzmeth.c
index 9c7f47566..d265947bb 100644
--- a/src/maths/ni/nipzmeth.c
+++ b/src/maths/ni/nipzmeth.c
@@ -19,6 +19,8 @@ static unsigned int Debug = 0;
 */
 #endif
 
+extern void zaddeq(double *a, int *amag, double x, int xmag, double y, int ymag);
+
 extern	int CKTpzTrapped;
 double	NIpzK;
 int	NIpzK_mag;
@@ -215,7 +217,7 @@ NIpzSym2(PZtrial **set, PZtrial *new)
     int		tmag;
     int		error;
     int		disc_mag;
-    int		new_mag;
+    int		new_mag = 0;
 
     error = OK;
 
diff --git a/src/maths/sparse/spfactor.c b/src/maths/sparse/spfactor.c
index 0bcf6a7ad..195181583 100644
--- a/src/maths/sparse/spfactor.c
+++ b/src/maths/sparse/spfactor.c
@@ -1709,9 +1709,13 @@ int Step;
     long  MinMarkowitzProduct, *pMarkowitzProduct;
     int  I;
     ElementPtr  pDiag;
-    int  NumberOfTies, Size = Matrix->Size;
+    int  NumberOfTies = 0;
+    int  Size = Matrix->Size;
+    
     ElementPtr  ChosenPivot;
-    RealNumber  Magnitude, Ratio, RatioOfAccepted, LargestInCol;
+    RealNumber  Magnitude, Ratio; 
+    RealNumber  RatioOfAccepted = 0;
+    RealNumber  LargestInCol;
     RealNumber  FindBiggestInColExclude();
 
     /* Begin `SearchDiagonal'. */
@@ -1838,10 +1842,13 @@ int Step;
 {
     int  I, Size = Matrix->Size;
     ElementPtr  pElement;
-    int  NumberOfTies;
+    int  NumberOfTies = 0;
     long  Product, MinMarkowitzProduct;
-    ElementPtr  ChosenPivot, pLargestElement;
-    RealNumber  Magnitude, LargestElementMag, Ratio, RatioOfAccepted, LargestInCol;
+    ElementPtr  ChosenPivot;
+    ElementPtr  pLargestElement = NULL;
+    RealNumber  Magnitude, LargestElementMag, Ratio;
+    RealNumber  RatioOfAccepted = 0;
+    RealNumber  LargestInCol;
     RealNumber  FindLargestInCol();
 
     /* Begin `SearchEntireMatrix'. */
diff --git a/src/maths/sparse/spoutput.c b/src/maths/sparse/spoutput.c
index 9511c72fd..51ba12973 100644
--- a/src/maths/sparse/spoutput.c
+++ b/src/maths/sparse/spoutput.c
@@ -137,7 +137,9 @@ spPrint(void *eMatrix, int PrintReordered, int Data, int Header)
     int  J = 0;
     int I, Row, Col, Size, Top;
     int StartCol = 1, StopCol, Columns, ElementCount = 0;
-    double  Magnitude, SmallestDiag, SmallestElement;
+    double  Magnitude; 
+    double  SmallestDiag = 0; 
+    double  SmallestElement = 0;
     double  LargestElement = 0.0, LargestDiag = 0.0;
     ElementPtr  pElement, *pImagElements;
     int  *PrintOrdToIntRowMap, *PrintOrdToIntColMap;
diff --git a/src/nghelp.c b/src/nghelp.c
index 0e9a1d3fe..1fdc3b195 100644
--- a/src/nghelp.c
+++ b/src/nghelp.c
@@ -102,7 +102,7 @@ cp_printword(s)
 */
 
 bool
-cp_getvar(char *n, int t, char *r)
+cp_getvar(char *n, int t, void *r)
 {
     return (FALSE);
 }