diff --git a/src/engine/engine_collision_box.c b/src/engine/engine_collision_box.c
index fae00bc6..77b202d3 100644
--- a/src/engine/engine_collision_box.c
+++ b/src/engine/engine_collision_box.c
@@ -316,52 +316,52 @@ int mjc_CapsuleBox(const mjModel* m, const mjData* d, mjContact* con,
         };
         mjtNum c[2];
       } d2;
-      d2 p, s, d /*, c, tmp1*/;
-      mjtNum u, v, w, e1, best /* ,e2 */, l /* , e3, e4 */;
+      d2 p, s, dd /*, c, tmp1*/;
+      mjtNum uu, vv, w, ee1, best /* ,e2 */, l /* , e3, e4 */;
 
       bestdist = bestdistmax;
 
       p.x = pos[0];
       p.y = pos[1];
-      d.x = halfaxis[0];
-      d.y = halfaxis[1];
+      dd.x = halfaxis[0];
+      dd.y = halfaxis[1];
       s.x = size2[0];
       s.y = size2[1];
 
-      l = sqrt(d.x * d.x + d.y * d.y);
+      l = sqrt(dd.x * dd.x + dd.y * dd.y);
 
-      u = d.x * s.y;
-      v = d.y * s.x;
-      w = d.x * p.y - d.y * p.x;
+      uu = dd.x * s.y;
+      vv = dd.y * s.x;
+      w = dd.x * p.y - dd.y * p.x;
 
 
       best = -1;
 
-      e1 = +u - v;
-      if ((e1 < 0) == (w < 0)) {
-        if (best < mju_abs(e1)) {
-          best = mju_abs(e1);
+      ee1 = +uu - vv;
+      if ((ee1 < 0) == (w < 0)) {
+        if (best < mju_abs(ee1)) {
+          best = mju_abs(ee1);
           c1 = 0;
         }
       }
-      e1 = -u - v;
-      if ((e1 < 0) == (w < 0)) {
-        if (best < mju_abs(e1)) {
-          best = mju_abs(e1);
+      ee1 = -uu - vv;
+      if ((ee1 < 0) == (w < 0)) {
+        if (best < mju_abs(ee1)) {
+          best = mju_abs(ee1);
           c1 = 1;
         }
       }
-      e1 = +u + v;
-      if ((e1 < 0) == (w < 0)) {
-        if (best < mju_abs(e1)) {
-          best = mju_abs(e1);
+      ee1 = +uu + vv;
+      if ((ee1 < 0) == (w < 0)) {
+        if (best < mju_abs(ee1)) {
+          best = mju_abs(ee1);
           c1 = 2;
         }
       }
-      e1 = -u + v;
-      if ((e1 < 0) == (w < 0)) {
-        if (best < mju_abs(e1)) {
-          best = mju_abs(e1);
+      ee1 = -uu + vv;
+      if ((ee1 < 0) == (w < 0)) {
+        if (best < mju_abs(ee1)) {
+          best = mju_abs(ee1);
           c1 = 3;
         }
       }
@@ -369,21 +369,21 @@ int mjc_CapsuleBox(const mjModel* m, const mjData* d, mjContact* con,
       // c.x = s.x * ((c1 / 2) ? -1 : 1);
       // c.y = s.y * ((c1 % 2) ? -1 : 1);
 
-      e1 = fabs(w) / l;
+      ee1 = fabs(w) / l;
       // e2 = best / l;
 
       // printf("%g %g      %g %g     %g %g\n",c.x,c.y,d.x,d.y,e1,e2);
 
       // tmp1.x = c.x - p.x;
       // tmp1.y = c.y - p.y;
-      e1 = d.x * d.x + d.y * d.y;
+      ee1 = dd.x * dd.x + dd.y * dd.y;
       // e2 = tmp1.x * d.x + tmp1.y * d.y;
       // e3 = e2 / e1;
 
 
       // printf("%g %g      %g %g     %g %g %g \n",c.x,c.y,d.x,d.y,e1,e2,e3);
 
-      e1 = p.x + (+s.y - p.y) / d.y * d.x;
+      ee1 = p.x + (+s.y - p.y) / dd.y * dd.x;
       // e2 = p.x + (-s.y - p.y) / d.y * d.x;
       // e3 = p.y + (+s.x - p.x) / d.x * d.y;
       // e4 = p.y + (-s.x - p.x) / d.x * d.y;
diff --git a/src/engine/engine_collision_driver.c b/src/engine/engine_collision_driver.c
index 7d8eddd9..cad80992 100644
--- a/src/engine/engine_collision_driver.c
+++ b/src/engine/engine_collision_driver.c
@@ -632,7 +632,7 @@ static int can_collide(const mjModel* m, int b) {
 
 // broadphase collision detector
 int mj_broadphase(const mjModel* m, mjData* d, int* pair, int maxpair) {
-  int i, j, b1, b2, toremove, cnt, npair = 0, nbody = m->nbody, ngeom = m->ngeom;
+  int b1, b2, toremove, cnt, npair = 0, nbody = m->nbody, ngeom = m->ngeom;
   mjtNum cov[9], cen[3], dif[3], eigval[3], frame[9], quat[4];
   mjtBroadphase *sortbuf, *activebuf;
   mjtNum *aabb;
@@ -727,13 +727,13 @@ int mj_broadphase(const mjModel* m, mjData* d, int* pair, int maxpair) {
   }
 
   // allocate sort buffer
-  i = sizeof(mjtBroadphase)/sizeof(mjtNum);
-  j = sizeof(mjtBroadphase)%sizeof(mjtNum);
-  sortbuf = (mjtBroadphase*)mj_stackAlloc(d, 2*bufcnt*(i + (j ? 1 : 0)));
-  activebuf = (mjtBroadphase*)mj_stackAlloc(d, 2*bufcnt*(i + (j ? 1 : 0)));
+  int quot = sizeof(mjtBroadphase)/sizeof(mjtNum);
+  int rem = sizeof(mjtBroadphase)%sizeof(mjtNum);
+  sortbuf = (mjtBroadphase*)mj_stackAlloc(d, 2*bufcnt*(quot + (rem ? 1 : 0)));
+  activebuf = (mjtBroadphase*)mj_stackAlloc(d, 2*bufcnt*(quot + (rem ? 1 : 0)));
 
   // init sortbuf with axis0
-  j = 0;
+  int k = 0;
   for (int i=1; i<nbody; i++) {
     // cannot colide
     if (!can_collide(m, i)) {
@@ -741,15 +741,15 @@ int mj_broadphase(const mjModel* m, mjData* d, int* pair, int maxpair) {
     }
 
     // init
-    sortbuf[2*j].body_ismax = i;
-    sortbuf[2*j].value = (float)aabb[6*i];
-    sortbuf[2*j+1].body_ismax = i + 0x10000;
-    sortbuf[2*j+1].value = (float)aabb[6*i+1];
-    j++;
+    sortbuf[2*k].body_ismax = i;
+    sortbuf[2*k].value = (float)aabb[6*i];
+    sortbuf[2*k+1].body_ismax = i + 0x10000;
+    sortbuf[2*k+1].value = (float)aabb[6*i+1];
+    k++;
   }
 
   // sanity check; SHOULD NOT OCCUR
-  if (j!=bufcnt) {
+  if (k!=bufcnt) {
     mju_error("Internal error in broadphase: unexpected bufcnt");
   }
 
@@ -828,7 +828,7 @@ endbroad:
 // test two geoms for collision, apply filters, add to contact list
 //  flg_user disables filters and uses usermargin
 void mj_collideGeoms(const mjModel* m, mjData* d, int g1, int g2, int flg_user, mjtNum usermargin) {
-  int i, num, type1, type2, condim;
+  int num, type1, type2, condim;
   mjtNum margin, gap, mix, friction[5], solref[mjNREF], solimp[mjNIMP];
   mjContact con[mjMAXCONPAIR];
   int ipair = (g2<0 ? g1 : -1);
@@ -841,7 +841,7 @@ void mj_collideGeoms(const mjModel* m, mjData* d, int g1, int g2, int flg_user,
 
   // order geoms by type
   if (m->geom_type[g1] > m->geom_type[g2]) {
-    i = g1;
+    int i = g1;
     g1 = g2;
     g2 = i;
   }
@@ -938,7 +938,7 @@ void mj_collideGeoms(const mjModel* m, mjData* d, int g1, int g2, int flg_user,
     }
 
     // consolidate good
-    i = 0;
+    int i = 0;
     for (int j=0; j<num; j++) {
       if (con[j].dim==0) {
         // different: copy
diff --git a/src/engine/engine_core_constraint.c b/src/engine/engine_core_constraint.c
index c83b228c..ac278441 100644
--- a/src/engine/engine_core_constraint.c
+++ b/src/engine/engine_core_constraint.c
@@ -1630,10 +1630,10 @@ void mj_makeConstraint(const mjModel* m, mjData* d) {
 
     // check that nnzJ was computed correctly
     if (d->nefc > 0) {
-      int nnz = d->efc_J_rownnz[d->nefc - 1] + d->efc_J_rowadr[d->nefc - 1];
-      if (d->nnzJ != nnz) {
+      int nnzJ = d->efc_J_rownnz[d->nefc - 1] + d->efc_J_rowadr[d->nefc - 1];
+      if (d->nnzJ != nnzJ) {
         mju_error("constraint Jacobian mis-allocation: found nnzJ=%d but allocated %d",
-                  nnz, d->nnzJ);
+                  nnzJ, d->nnzJ);
       }
     }
   } else if (d->nefc > nefc_allocated) {
diff --git a/src/engine/engine_core_smooth.c b/src/engine/engine_core_smooth.c
index 599d2e47..6c6a027a 100644
--- a/src/engine/engine_core_smooth.c
+++ b/src/engine/engine_core_smooth.c
@@ -1562,28 +1562,28 @@ void mj_rnePostConstraint(const mjModel* m, mjData* d) {
   // forward pass over bodies: compute cacc, cfrc_int
   mjtNum cacc[6], cfrc_body[6], cfrc_corr[6];
   mju_zero(d->cfrc_int, 6);
-  for (int i=1; i<m->nbody; i++) {
+  for (int j=1; j<m->nbody; j++) {
     // get body's first dof address
-    int bda = m->body_dofadr[i];
+    int bda = m->body_dofadr[j];
 
     // cacc = cacc_parent + cdofdot * qvel + cdof * qacc
-    mju_mulDofVec(cacc, d->cdof_dot+6*bda, d->qvel+bda, m->body_dofnum[i]);
-    mju_add(d->cacc+6*i, d->cacc+6*m->body_parentid[i], cacc, 6);
-    mju_mulDofVec(cacc, d->cdof+6*bda, d->qacc+bda, m->body_dofnum[i]);
-    mju_addTo(d->cacc+6*i, cacc, 6);
+    mju_mulDofVec(cacc, d->cdof_dot+6*bda, d->qvel+bda, m->body_dofnum[j]);
+    mju_add(d->cacc+6*j, d->cacc+6*m->body_parentid[j], cacc, 6);
+    mju_mulDofVec(cacc, d->cdof+6*bda, d->qacc+bda, m->body_dofnum[j]);
+    mju_addTo(d->cacc+6*j, cacc, 6);
 
     // cfrc_body = cinert * cacc + cvel x (cinert * cvel)
-    mju_mulInertVec(cfrc_body, d->cinert+10*i, d->cacc+6*i);
-    mju_mulInertVec(cfrc_corr, d->cinert+10*i, d->cvel+6*i);
-    mju_crossForce(cfrc, d->cvel+6*i, cfrc_corr);
+    mju_mulInertVec(cfrc_body, d->cinert+10*j, d->cacc+6*j);
+    mju_mulInertVec(cfrc_corr, d->cinert+10*j, d->cvel+6*j);
+    mju_crossForce(cfrc, d->cvel+6*j, cfrc_corr);
     mju_addTo(cfrc_body, cfrc, 6);
 
     // set cfrc_int = cfrc_body - cfrc_ext
-    mju_sub(d->cfrc_int+6*i, cfrc_body, d->cfrc_ext+6*i, 6);
+    mju_sub(d->cfrc_int+6*j, cfrc_body, d->cfrc_ext+6*j, 6);
   }
 
   // backward pass over bodies: accumulate cfrc_int from children
-  for (int i=m->nbody-1; i>0; i--) {
-    mju_addTo(d->cfrc_int+6*m->body_parentid[i], d->cfrc_int+6*i, 6);
+  for (int j=m->nbody-1; j>0; j--) {
+    mju_addTo(d->cfrc_int+6*m->body_parentid[j], d->cfrc_int+6*j, 6);
   }
 }
diff --git a/src/engine/engine_plugin.cc b/src/engine/engine_plugin.cc
index 046e5b1c..189a0eef 100644
--- a/src/engine/engine_plugin.cc
+++ b/src/engine/engine_plugin.cc
@@ -380,8 +380,8 @@ const mjpPlugin* mjp_getPluginUnsafe(const char* name, int* slot, int nslot) {
     return nullptr;
   }
 
-  Global& plugin = GetGlobal();
-  PluginTable* table = &plugin.table();
+  Global& plugins = GetGlobal();
+  PluginTable* table = &plugins.table();
   int found_slot = 0;
   while (table) {
     for (int i = 0;
diff --git a/src/engine/engine_support.c b/src/engine/engine_support.c
index be3c665c..ae882b26 100644
--- a/src/engine/engine_support.c
+++ b/src/engine/engine_support.c
@@ -909,14 +909,14 @@ void mj_addM(const mjModel* m, mjData* d, mjtNum* dst,
         M_rowadr[i] = i*nv;
 
         // reverse order
-        for (int j=0; j<adr1/2; j++) {
-          mjtNum tmp = M[i*nv+j];
-          M[i*nv+j] = M[i*nv+adr1-1-j];
-          M[i*nv+adr1-1-j] = tmp;
+        for (int k=0; k<adr1/2; k++) {
+          mjtNum tmp = M[i*nv+k];
+          M[i*nv+k] = M[i*nv+adr1-1-k];
+          M[i*nv+adr1-1-k] = tmp;
 
-          int tmpi = M_colind[i*nv+j];
-          M_colind[i*nv+j] = M_colind[i*nv+adr1-1-j];
-          M_colind[i*nv+adr1-1-j] = tmpi;
+          int tmpi = M_colind[i*nv+k];
+          M_colind[i*nv+k] = M_colind[i*nv+adr1-1-k];
+          M_colind[i*nv+adr1-1-k] = tmpi;
         }
       }
     }
@@ -924,10 +924,10 @@ void mj_addM(const mjModel* m, mjData* d, mjtNum* dst,
     // make symmetric
     for (int i=1; i<nv; i++) {
       if (!m->dof_simplenum[i]) {
-        for (int adr=nv*i; adr<nv*i+M_rownnz[i]-1; adr++) {
+        for (int k=nv*i; k<nv*i+M_rownnz[i]-1; k++) {
           // add to row given by column index
-          adr1 = nv*M_colind[adr] + M_rownnz[M_colind[adr]]++;
-          M[adr1] = M[adr];
+          adr1 = nv*M_colind[k] + M_rownnz[M_colind[k]]++;
+          M[adr1] = M[k];
           M_colind[adr1] = i;
         }
       }
diff --git a/src/engine/engine_util_misc.c b/src/engine/engine_util_misc.c
index 656f9bf0..256f2a35 100644
--- a/src/engine/engine_util_misc.c
+++ b/src/engine/engine_util_misc.c
@@ -81,7 +81,7 @@ static mjtNum wrap_circle(mjtNum* pnt, const mjtNum* d, const mjtNum* sd, mjtNum
   mjtNum dif[2] = {d[2]-d[0], d[3]-d[1]};
   mjtNum a, tmp[2], dd, sqrt0, sqrt1;
   mjtNum sol[2][2][2], good[2], wlen;
-  int i, sgn;
+  int sgn;
 
   // either point inside circle or circle too small: no wrap
   if (sqlen0<sqrad || sqlen1<sqrad || rad<mjMINVAL) {
@@ -138,7 +138,7 @@ static mjtNum wrap_circle(mjtNum* pnt, const mjtNum* d, const mjtNum* sd, mjtNum
   }
 
   // select the better solution
-  i = (good[0]>good[1] ? 0 : 1);
+  int i = (good[0]>good[1] ? 0 : 1);
   pnt[0] = sol[i][0][0];
   pnt[1] = sol[i][0][1];
   pnt[2] = sol[i][1][0];
diff --git a/src/engine/engine_vfs.c b/src/engine/engine_vfs.c
index f0f91945..08053d6c 100644
--- a/src/engine/engine_vfs.c
+++ b/src/engine/engine_vfs.c
@@ -24,9 +24,10 @@
 
 // strip path prefix from filename
 static void vfs_strippath(char* newname, const char* oldname) {
-  int i, sz = strlen(oldname);
+  int sz = strlen(oldname);
 
   // find last delimiter
+  int i;
   for (i=sz-1; i>=0; i--) {
     if (oldname[i]=='\\' || oldname[i]=='/') {
       break;
@@ -45,9 +46,9 @@ static void vfs_strippath(char* newname, const char* oldname) {
   mju_strncpy(newname, oldname+i+1, mjMAXVFSNAME);
 
   // make lowercase
-  for (int i=strlen(newname)-1; i>=0; i--) {
-    if (newname[i]>='A' && newname[i]<='Z') {
-      newname[i] = (char)(((int)newname[i]) +'a' - 'A');
+  for (int j=strlen(newname)-1; j>=0; j--) {
+    if (newname[j]>='A' && newname[j]<='Z') {
+      newname[j] = (char)(((int)newname[j]) +'a' - 'A');
     }
   }
 }
diff --git a/src/engine/engine_vis_visualize.c b/src/engine/engine_vis_visualize.c
index e0ae56a0..b317eafd 100644
--- a/src/engine/engine_vis_visualize.c
+++ b/src/engine/engine_vis_visualize.c
@@ -464,12 +464,12 @@ void mjv_addGeoms(const mjModel* m, mjData* d, const mjvOption* vopt,
   int objtype, category;
   mjtNum sz[3], mat[9], selpos[3];
   mjtNum catenary[3*mjNCATENARY];
-  mjtNum *cur, *nxt, *xpos, *xfrc;
+  mjtNum *cur, *nxt, *xfrc;
   mjtNum vec[3], end[3], axis[3], rod, len, det, tmp[9], quat[4];
   mjtByte broken;
   mjvGeom* thisgeom;
   mjvPerturb localpert;
-  float scl = m->stat.meansize, rgba[4];
+  float scl = m->stat.meansize;
 
   // make default pert if missing
   if (!pert) {
@@ -612,12 +612,12 @@ void mjv_addGeoms(const mjModel* m, mjData* d, const mjvOption* vopt,
           mjtNum density = mass / mju_max(mjMINVAL, volume);
 
           // scale = root3(density)
-          mjtNum scl = mju_pow(density*0.001, 1.0/3.0);
+          mjtNum scale = mju_pow(density*0.001, 1.0/3.0);
 
           // scale sizes, so that box/ellipsoid with density of 1000 has same mass
-          sz[0] *= scl;
-          sz[1] *= scl;
-          sz[2] *= scl;
+          sz[0] *= scale;
+          sz[1] *= scale;
+          sz[2] *= scale;
         }
 
         // construct geom
@@ -659,6 +659,7 @@ void mjv_addGeoms(const mjModel* m, mjData* d, const mjvOption* vopt,
                         pert->refselpos[0], pert->refselpos[1], pert->refselpos[2]);
 
       // prepare color
+      float rgba[4];
       mixcolor(rgba, m->vis.rgba.constraint,
                (pert->active & mjPERT_TRANSLATE)>0,
                (pert->active2 & mjPERT_TRANSLATE)>0);
@@ -683,6 +684,7 @@ void mjv_addGeoms(const mjModel* m, mjData* d, const mjvOption* vopt,
       START
 
       // prepare color, use inertia color
+      float rgba[4];
       mixcolor(rgba, m->vis.rgba.inertia,
                (pert->active & mjPERT_ROTATE)>0,
                (pert->active2 & mjPERT_ROTATE)>0);
@@ -1681,7 +1683,7 @@ void mjv_addGeoms(const mjModel* m, mjData* d, const mjvOption* vopt,
   for (int i=1; i<m->nbody; i++) {
     if (!mju_isZero(d->xfrc_applied+6*i, 6) && (category & catmask)) {
       // point of application and force
-      xpos = d->xipos+3*i;
+      mjtNum *xpos = d->xipos+3*i;
       xfrc = d->xfrc_applied+6*i;
 
       // force perturbation